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		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=161</id>
		<title>Intrebari Frecvente</title>
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		<updated>2014-01-31T08:04:18Z</updated>

		<summary type="html">&lt;p&gt;8fold: /* Unde pot găsi un forum românesc dedicat discuțiilor despre Bitcoin? */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
:Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;). Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Adresă Bitcoin]]. Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
:A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
:Există o varietate de moduri de a dobândi Bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Acceptă Bitcoin ca plată pentru bunuri sau servicii.&lt;br /&gt;
* Cel mai obișnuit mod de a cumpăra Bitcoin sunt [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* Există mai multe servicii, unde poți [[Buying_Bitcoins_(the_noob_version)|trade them]] pentru monezi tradiționale.&lt;br /&gt;
* Găsește pe cineva care vinde Bitcoin în persoană pentru cash prin [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participă într-un [[Pooled mining|mining pool]].&lt;br /&gt;
* De asemenea, dacă echipamentul de minerit este destul de performant, minatul solo este posibil prin crearea unui nou [[block]] ( Rezolvarea unui block produce în prezent 25 Bitcoin, plus taxele de tranzacție).&lt;br /&gt;
* Vizită site-urile care oferă [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
=== Garantează Bitcoin un flux gratis de bani? ===&lt;br /&gt;
&lt;br /&gt;
:Deoarece Bitcoin este o tehnologie nouă, poate crea confuzie cu privire la ce este și cum funcționează. Uneori, datorită prezentării, este privit ca una dintre următoarele lucruri:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;O schemă &amp;quot;îmbogățește-te peste noapte&amp;quot; online.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;O portiță în piața economiei, prin instalarea sa garantează un flux regulat de cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;O investiție sigură care va rezulta aproape întotdeauna un profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
&lt;br /&gt;
:De fapt, niciuna dintre scenariile prezentate mai sus sunt adevărate. Să privim cu atenție scenariile în mod independent.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
;Este Bitcoin o schemă care poate îmbogății peste noapte ?&lt;br /&gt;
&lt;br /&gt;
:Dacă ai petrecut destul timp pe internet, cel mai probabil ai văzut multe reclame pentru fel și fel de metode care te pot îmbogății peste noapte. Reclamele acestea deobicei oferă profituri imense în schimbul a câteva ore investite. Aceste metode sunt, în majoritatea cazurilor, scheme piramidale care generează bani de la angajații săi proprii și nu oferă nimic în schimb ce reprezintă o valoare reală. Majoritatea lor te vor convinge să cumperi un pachet care îți va câștiga sume în jurul sutelor zilnic, dar defapt prin tine, distribuie reclamă și mai multă. În concluzie rezultând profit pentru cel care deține jocul piramidal.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin este în nici un fel similar cu aceste scheme. Bitcoin nu promite profituri excepționale. Nu există nici o modalitate prin care dezvoltătorii pot face bani cu implicarea ta sau de a lua bani de la tine. Obținerea unui Bitcoin este aproape imposibil fără consimțământul proprietarului. Acest fapt reprezintă un punct forte al monedei virtuale. Bitcoin este o monedă experimentală, virtuală care poate reuși sau poate eșua. Nici unul dintre dezvoltătorii săi se așteaptă să se îmbogățească pe urmă sa.&lt;br /&gt;
&lt;br /&gt;
:Un răspuns mai detaliat la această întrebare poate fi găsit [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
;Voi face bani instalând clientul?&lt;br /&gt;
&lt;br /&gt;
:Majoritatea indivizilor care folosesc Bitcoin nu câștiga nimic prin a face acest lucru. Iar clientul implicit nu a fost creat pentru a câștiga Bitcoin. O mică minoritate de oameni cu hardware dedicat, de înaltă performanță dobândesc Bitcoin prin &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generează bitcoins, vezi [[#What is mining?|What is mining?]]) cu un soft special, dar aderarea în comunitatea Bitcoin nu ar trebui să fie greșit interpretată ca fiind drumul spre bogăție. Marea majoritate a utilizatorilor se implică pentru că conceptualitatea proiectului este foarte interesantă, prin urmare nu au nimic de câștigat prin asta.  Acesta este, de asemenea, motivul pentru care nu veți găsi speculații multe cu privire la repercusiuni politice sau economice legate de Bitcoin oriunde pe acest site: Dezvoltătorii Bitcoin își datorează devotamentul lor pentru beneficiile intelectuale, decât cele de natură monetară. Bitcoin își face primii pași mărunți: poate ajunge într-o poziție unde va crea lucruri grozave, dar acum are ceva de oferit doar celor care au nevoie de un stimulus interesant din punct de vedere conceptual si care face parte din tehnologia de ultima oră.&lt;br /&gt;
 &lt;br /&gt;
  &lt;br /&gt;
&lt;br /&gt;
;Ca o investiție, este Bitcoin un lucru sigur? &lt;br /&gt;
&lt;br /&gt;
:Bitcoin este o monedă electronică nouă și interesantă, valoarea acestuia nu este susținută de către nici un guvern sau organizație. Ca orice valută, o anumită parte din valoare se justifică prin faptul că oamenii sunt dispuși să facă comerț în schimbul bunurilor sau servicilor. Rata de schimb a valutei fluctuează în continuu, și câteodată în mod nesăbuit. Este lipsită de recunoaștere globală și este vunerabil la manipulare de către terți care dispun de o finanțare modestă. Incidente de securitate, cum ar fi compromisul site-urilor sau a conturilor pot declanșa lichidări majore. Diferite fluctuații pot crea o serie de bucle pozitive, acestea cauzând fluctuații mult mai mari al cursului de schimb. Oricine care investește bani în Bitcoin trebuie să înțeleagă riscurile la care sunt predispuși, și să considere valuta un curs de schimb volatil. Odată ce Bitcoin devine mai cunoscut și acceptat, cursul se va stabiliza, dar pentru moment este imprevizibil. Orice investiție în Bitcoin ar trebui făcut cu atenție și cu un plan clar de a mitiga riscul.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpăra bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
Este posibilă cumpărarea bitcoinilor fizici cu PayPal, dar este o operațiune dificilă și/sau scumpă pentru bitcoinii non-fizici, datorită riscului însemnat pentru vânzător. &lt;br /&gt;
&lt;br /&gt;
Deși este posibilă găsirea unui individ ce dorește să-ți vândă Bitcoini via PayPal (posibil via [http://www.bitcoin-otc.com/ #bitcoin-otc]), majoritatea schimburilor virtuale nu permit finanțarea prin PayPal. Acest lucru se datorează cazurilor repetate în care cineva plătește bitcoinii prin PayPal, primește bitcoinii cuveniți, iar mai apoi se plânge în mod fraudulos către PayPal pe motiv că nu și-ar fi primit achiziția. PayPal adesea ia partea cumpărătorului fraudulos în acest caz, ce-nseamnă că orice vânzător trebuie să-și acopere riscul cu taxe mai mari sau să refuze să accepte PayPal cu totul.&lt;br /&gt;
&lt;br /&gt;
Cumpărarea de Bitcoini de la indivizi în acest fel este posibil, dar este necesar ca vânzătorul să aibă încredere că acel cumpărător nu va depune o cerere către PayPal de restituire a plății.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot găsi un forum românesc dedicat discuțiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Pe [[Bitcointalk.org]], forumul oficial Bitcoin, există o comunitate din ce în ce mai mare de români interesaţi de Bitcoin, vizitaţi [https://bitcointalk.org/index.php?board=108.0 &#039;&#039;&#039;Forumul Românesc Bitcoin&#039;&#039;&#039;].&lt;br /&gt;
&lt;br /&gt;
=== Cum se creează noi bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Numărul bitcoinilor în timp, presupunând un interval perfect, de 10 minute.]]&lt;br /&gt;
Noi bitcoini sunt generați de rețea prin procesul numit „[[Minat de bitcoini|minare]]”. Într-un proces ce este similar unei loterii, nodurile miniere ale rețelei sunt răsplătite cu bitcoini de fiecare dată când găsesc o soluție unei anumite probleme matematice (și prin urmare crează un nou [[bloc]]). Crearea unui bloc este o metodă de verificare cu o dificultate ce variază odată cu puterea de calcul totală a rețelei. Recompensa pentru rezolvarea unui bloc este ajustată în mod automat, astfel încât, la fiecare patru ani de operare a rețelei Bitcoin, sunt creați jumătate din numărul de bitcoini existenți în precedenții 4 ani. {{formatnum:10500000}} bitcoini au fost creați în primii (aproximativ) 4 ani, din ianuarie 2009 până în noiembrie 2012. Prin urmare, la fiecare patru ani după aceea, această cantitate se înjumătățește, astfel încât va fi de {{formatnum:5250000}} pentru anii 4-8, {{formatnum:2625000}} pentru anii 8-12, ș.a.m.d. Astfel, numărul total de bitcoini aflați în existență nu va depăși niciodată {{formatnum:21000000}}.&lt;br /&gt;
&lt;br /&gt;
Blocurile sunt minate la fiecare 10 minute (în medie), iar pentru primii 4 ani ({{formatnum:210000}} blocuri), fiecare bloc conținea 50 bitcoini noi. Pe măsură ce puterea de procesare direcționată către minat se schimbă, dificultatea creării de noi bitcoini variază. Acest factor de dificultate este calculat la fiecare 2016 blocuri și este bazat pe timpul necesar generării precedentelor 2016 blocuri. Vezi secțiunea [[Minat de bitcoini|minat]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numărul total de bitcoini la ora actuală?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Numărătoarea curentă]. Vezi și [https://blockchain.info/charts/total-bitcoins graficul numărului total aflați în circulație]&lt;br /&gt;
&lt;br /&gt;
Numărul de blocuri înmulțit cu cantitatea monedelor fiecărui bloc este numărul de monede aflate în existență. Valoarea monetară a unui bloc este de 50 BTC pentru primele {{formatnum:210000}} blocuri, 25 BTC pentru următoarele {{formatnum:210000}} blocks, apoi 12.5 BTC, 6.25 BTC, etc.&lt;br /&gt;
&lt;br /&gt;
=== Cât de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
Un bitcoin poate fi divizat până la 8 cifre decimale. Prin urmare, 0.00000001 BTC este cantitatea cea mai mică ce poate fi procesată într-o tranzacție. Dacă este necesar, protocolul și software-ul aferent pot fi modificate pentru a manipula cantități chiar mai mici.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominările bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
Există multe discuții despre numirea acestor fracțiuni de bitcoini. Principalele candidate sunt:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0,01 BTC = 1 cBTC = 1 centibitcoin (denumit și bitcent)&lt;br /&gt;
* 0,001 BTC = 1 mBTC = 1 milibitcoin (denumit și mbit sau milibit sau chiar bitmil)&lt;br /&gt;
* 0,000 001 BTC = 1 μBTC = 1 microbitcoin (denumit și ubit (pronunțat iu-bit) sau microbit)&lt;br /&gt;
&lt;br /&gt;
Cele de mai sus aplică prefixele acceptate pe plan internațional (SI) pentru sutimi, miimi și milionimi. Există multe argumente împotriva cazului special pentru 0,01 BTC, deoarece este puțin probabil că va reprezenta vreodată ceva semnificativ, datorită faptului că economia Bitcoinului e în creștere (cu siguranță nu va fi echivalentul a 0,01 USD, GBP sau EUR). În egală măsură, includerea unor denominări ale valutelor naționale (cum ar fi „cent”, „nickel” - 5 cenți US, „dime” - 10 cenți US, „penny” - 1 cent GB, „liră”, „kopek” - 1/100 ruble ș.a.m.d.) este descurajată; aceasta este o monedă globală.&lt;br /&gt;
&lt;br /&gt;
O excepție este „satoshi”-ul, cea mai mică denominare monetară posibilă.&lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronunțat satóși)&lt;br /&gt;
nume dat în onoarea lui Satoshi Nakamoto, pseudonimul inventatorului Bitcoin&lt;br /&gt;
&lt;br /&gt;
Pentru o privire de ansamblu a tuturor unităților definite ale Bitcoinilor (incluzându-le pe cele mai puțin comune sau de nișă), vezi secțiunea [[unități]].&lt;br /&gt;
&lt;br /&gt;
Discuții suplimentare pe acest subiect pot fi găsite pe forumuri (eng), aici:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum funcționează înjumătățirea când numărul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Recompensa va ajunge, într-un final, de la 0.00000001 BTC la zero și nu vor mai fi creați bitcoini noi.&lt;br /&gt;
&lt;br /&gt;
Calcularea răsplatei per bloc se face prin schimbare către dreapta în biți a unui număr întreg de 64 biți, ceea ce înseamnă că este împărțit la doi și aproximat în jos. Numărul întreg este egal cu valoarea în BTC * 100.000.000, deoarece, în mod intern în clientul software standard, toate soldurile în Bitcoin și valorile sunt stocate ca și numere întregi non-negative (0 sau pozitive).&lt;br /&gt;
&lt;br /&gt;
Cu o recompensă inițială de 50 BTC/bloc, vor fi necesare multe intervale a câte 4 ani pentru ca recompensa de bloc să ajungă la zero.&lt;br /&gt;
&lt;br /&gt;
=== Cât timp va dura până vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
Ultimul bloc ce va genera monede va fi blocul #6.929.999, care în mod normal ar fi generat în anul 2140 (sau în preajma acestuia). Numărul total de bitcoini aflați în circulație va rămâne atunci static, la 20.999.999,9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Chiar și dacă precizia permisă ar fi extinsă de la 8 decimale (câte sunt în prezent), numărul total al BTC în circulație va fi întotdeauna cu puțin sub 21 milioane (presupunând că, în rest, totul rămâne la fel). De exemplu, cu o precizie de 16 decimale, în final vor fi 20.999.999,999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Dacă nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Desigur! Chiar și înainte ca generarea de monede să înceteze, folosirea [[Comisioane de tranzacție|comisioanelor de tranzacție]] va crea, cel mai probabil, noi blocuri, mai valoroase pentru comisioane decât noile monede create. Când aceasta încetează, aceste comisioane vor menține posibilitatea de a folosi bitcoini și rețeaua Bitcoin. Nu există o limită practică a numărului de blocuri care va fi minat în viitor.&lt;br /&gt;
&lt;br /&gt;
=== Dar dacă nu mai sunt generate monezi, ce se întâmplă când se pierd bitcoini? Nu ar fi o problemă? ===&lt;br /&gt;
&lt;br /&gt;
Datorită legii economice a cererii și ofertei, atunci când mai puțini bitcoini sunt disponibili, cei rămași vor avea o cerere mai mare și prin urmare valoarea acestora va fi mai mare. Așadar, pe măsură ce bitcoinii sunt pierduți, cei rămași vor crește într-un final în valoare, pentru a compensa. Pe măsură ce valoarea unui bitcoin crește, numărul de bitcoini necesar cumpărării unui obiect &#039;&#039;des&#039;&#039;crește. Acesta este un model economic deflaționar. În timp ce valoarea medie a unei tranzacții se reduce, acestea vor fi, probabil, denominate în subunități ale bitcoinului precum milibitcoini sau microbitcoini (vezi mai sus).&lt;br /&gt;
&lt;br /&gt;
Protocolul Bitcoin folosește o bază a unităților de 1/100.000.000 (un „satoshi”), dar biți nefolosiți sunt disponibili în câmpurile protocolului, ce ar putea fi utili pentru a stabili subdiviziuni chiar mai mici.&lt;br /&gt;
&lt;br /&gt;
=== Dacă fiecare tranzacție este emisă prin rețea, atunci este Bitcoin scalabil? ===&lt;br /&gt;
&lt;br /&gt;
Protocolul Bitcoin admite programe de tip client ce pot folosi platforma fără a descărca întregul istoric al tranzacțiilor. Pe măsura creșterii traficului și acest lucru devine tot mai critic, implementări ale conceptului vor fi dezvoltate. Noduri de rețea complete vor deveni, pe viitor, un serviciu mai specializat.&lt;br /&gt;
&lt;br /&gt;
Odată cu anumite modificări de software, noduri de Bitcoin complete vor putea ține pasul cu ușurință cu sisteme precum VISA sau MasterCard combinate, folosind resurse fizice modeste (un singur server de vârf conform standardelor actuale). De notat este faptul că rețeaua MasterCard este structurată într-un fel similar Bitcoinului - mai precis, o rețea de difuzare de tip „peer to peer” (legătură directă între utilizatori).&lt;br /&gt;
&lt;br /&gt;
== Economie ==&lt;br /&gt;
=== De unde provine valoarea bitcoinilor? Ce „susține” bitcoinii? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoinii au valoare pentru că sunt utili și pentru că sunt  [[Furnizare controlată a valutei|rari]]. Pe măsură ce vor fi acceptați de tot mai mulți comercianți, valoarea lor se va [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabiliza] (eng). Vezi și [[Schimb|lista paginilor care acceptă bitcoini]].&lt;br /&gt;
&lt;br /&gt;
Atunci când spunem că o valută este „susținută” de aur, ne referim la faptul că există promisiunea că poți să schimbi acea monedă pentru aur. Bitcoinii, la fel ca și dolarii sau euro, nu sunt susținuți de nimic altceva în afară de varietatea comercianților care îi acceptă.&lt;br /&gt;
&lt;br /&gt;
Esită o concepție greșită cum că bitcoinii și-ar lua valoarea din costul electricității necesare generării lor. Costul nu este tot una cu valoare - angajarea a 1.000 de oameni pentru a săpa o groapă imensă în pământ ar putea fi costisitoare, dar nu și de valoare. De asemenea, deși raritatea este un necesar critic pentru o monedă utilă, ea singură nu conferă valoare niciunui lucru. De exemplu, ampretele tale sunt rare, dar asta nu înseamnă că ele au o valoare de schimb.&lt;br /&gt;
&lt;br /&gt;
În mod alternativ, este necesară adăugarea că, deși legea cererii și a ofertei se aplică, aceasta nu garantează valoarea bitcoinilor pe viitor. Dacă încrederea în monedă este pierdută,  atunci nu va mai conta dacă influxul nu va mai putea fi susținut. Cererea va pica, toți deținătorii încercând să scape de monezile lor. Un bun exemplu al acestui lucru poate fi văzut la valutele naționale, în cazurile când statul în cauză s-a dizolvat și prin urmare, nu mai este creată valută (autoritatea centrală ce se ocupă de acest lucru încetând a mai exista), cu toate acestea cererea pentru monedă scăzând drastic datorită dispariției încrederii în puterea de cumpărare a acesteia. Desigur, bitcoinii nu au o autoritate centrală care să se ocupe de influxul monetar, dar acest lucru nu poate preveni erodarea confienței datorită situațiilor ce nu sunt neapărat predictibile.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
&lt;br /&gt;
Da, în același fel în care și euro și dolarul sunt. Ele au valoare doar în schimburile valutare și nu au vreo valoare intrinsecă. Dacă toți comercianții ar refuza, dintr-o dată, acceptarea dolarilor, a euro sau a bitcoinilor, „bula” s-ar sparge și valoarea lor ar scădea la zero.&lt;br /&gt;
Dar acest lucru este puțin probabil să se întâmple: chiar și în Somalia, unde guvernul a picat acum 20 de ani, [http://en.wikipedia.org/wiki/Somali_shilling shillingii somalezi] (eng) încă sunt acceptați ca formă de plată.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schemă piramidală/Ponzi? ===&lt;br /&gt;
&lt;br /&gt;
Într-o schemă piramidală, fondatorii conving investitorii că vor face profit. Bitcoin nu aduce o astfel de garanție. Nu există vreo entitate centrală, doar indivizi ce clădesc o economie.&lt;br /&gt;
&lt;br /&gt;
O schemă ponzi/piramidală este un joc „cu sumă zero”. Cei ce o adoptă timpuriu pot doar să profite la pierderea celor ce-o fac târziu. Bitcoinii au posibilitatea rezultatelor dublu câștigătoare. Cei ce adoptă moneda timpuriu pot profita de creșterea în valoare. Ceilalți și desigur, societatea în general, va profita de utilitatea unei valute „de la egal la egal” (peer-to-peer) stabile, rapide, puțin costisitoare și larg acceptate.&lt;br /&gt;
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Faptul că cei ce acceptă moneda devreme vor beneficia mai mult nu face din acest lucru o schemă piramidală. Toate investițiile bune în companii de succes au această calitate.&lt;br /&gt;
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=== Nu cumva Bitcoin favorizează pe nedrept investitorii inițiali? ===&lt;br /&gt;
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Investitorii inițiali au un număr mare de bitcoini acum deoarece și-au asumat riscul și au alocat resurse într-o tehnologie inovativă și nedemonstrată. Prin acest lucru, ei au ajutat sistemul Bitcoin să devină ceea ce este acum și ceea ce va fi în viitor (preferabil un sistem digital de plăți omniprezent). Este doar corect ca ei să fie beneficiarii propriei investiții de succes.&lt;br /&gt;
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În orice caz, orice bitcoin generat va schimba mâinile probabil de zeci de ori ca mediu de schimb, așadar profitul dobândit din distribuția inițială va fi insignifiant, comparativ cu comerțul total datorat Bitcoin.&lt;br /&gt;
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=== Pierderea de portofele și faptul că numărul de bitcoini este finit nu ar cauza deflație excesivă, distrugând Bitcoinul? ===&lt;br /&gt;
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Griji datorate distrugerii sistemului Bitcoin de către sistemul deflaționist ce-l caracterizează nu sunt cu totul fondate. Spre deosebire de majoritatea valutelor, bazate pe un model inflaționist, datorită faptului că instituțiile ce le susțin creează tot mai multe unități, rețeaua Bitcoin va trece cel mai probabil printr-o deflație graduală odată cu trecerea timpului. Această monedă criptografică este unică prin faptul că doar o cantitate mică de unități va fi produsă vreodată (21 de milioane, pentru exactitate), numărul acesta fiind stabilit încă de la conceperea proiectului, iar unitățile vor fi create la o rată predictibilă.&lt;br /&gt;
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De asemenea, utilizatorii bitcoinilor sunt expuși unui pericol ce nu prezintă amenințări pentru orice altă monedă: dacă un deținător își pierde portofelul, banii săi se pierd pentru totdeauna, dacă nu și-l găsește din nou, iar bitcoinii respectivi nu vor mai fi accesibili pentru nimeni, dispărând complet din circulație și devenind practic de nefolosit. Pe măsură ce oamenii își pierd portofelele, numărul total de monezi utilizabile va scădea încetul cu încetul.&lt;br /&gt;
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Prin urmare, platforma Bitcoin pare să întâmpine o problemă unică. În timp ce majoritatea valutelor sunt caracterizate de inflație în timp, Bitcoin va suferi, cel mai probabil, opusul. Timpul va demonstra această pierdere irecuperabilă a unui număr tot mai mare de monede. Un număr deja mic va fi diminuat tot mai mult. Și pe măsură ce rata de apariție a lor scade progresiv, legea cererii și a ofertei prezice că valoarea lor va crește continuu.&lt;br /&gt;
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Astfel, conceptul Bitcoini este din nou „condamnat” să intre teritorii misterioase deoarece nimeni nu știe cu exactitate ce se întâmplă cu o monedă tot mai valoroasă. Mulți economiști susțin că un nivel scăzut de inflație este un lucru bun pentru o monedă, dar niciunul nu cunoaște ce se întâmplă cu monedă ce suferă o ușoară deflație. Deși acest lucru nu poate fi numit un fenomen rar, o deflație înceată și constantă este un lucru nemaiîntâlnit. Există multă speculație, dar nu există date experimentale pentru a susține vreo teorie în defavoarea alteia.&lt;br /&gt;
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Acestea fiind spuse, există un mecanism instaurat care să combată consecințele evidente. O deflație extremă ar face ca majoritatea monezilor să devină impractice: dacă un singur dolar canadian ar putea aduce deținătorului său o mașină, cum ar putea cineva să cumpere, spre exemplu, o bomboană sau o pânine? Chiar și cu penny, acest lucru ar aduce cumpărătorului mai mult din acestea decât ar putea transporta. Bitcoinii, în schimb, oferă o soluție elegantă: divizibiltate infinită. Bitcoinii pot fi împărțiți în cantități atât de mici cât și-ar putea dori cineva. Așadar, indiferent cât de valoroși devin bitcoinii, un individ ar putea să-i comercializeze în cantități practice&lt;br /&gt;
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De fapt, divizibilitatea infinită ar trebui să permită sistemului să funcționeze în cazuri de pierderi extreme de portofele. Chiar dacă, în viitorul îndepărtat, un număr seminifativ de oameni și le-ar pierde, astfel încât ar rămâne un singur bitcoin sau o fracție din acesta, sistemul ar trebui să continue să existe fără probleme. Nimeni nu poate susține cu certitudine ce se va întâmpla, dar deflația s-ar putea dovedi a fi o amenințare mult mai mică decât s-ar aștepta multe persoane.&lt;br /&gt;
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Pentru mai multe informații, vezi și pagina [[Spirală deflaționistă|spiralei deflaționiste]].&lt;br /&gt;
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=== Dar dacă cineva ar cumpăra fiecare bitcoin existent? ===&lt;br /&gt;
Piețele Bitcoin sunt competitive, iar asta înseamnă că prețul unei monede va crește sau scădea în funcție de cererea și oferta la anumite niveluri de preț. Doar o mică parte a bitcoinilor creați până în prezent se găsesc în piețele de schimb valutar. Deci, deși tehnic vorbind, un cumpărător foarte înstărit ar putea cumpăra toată oferta existentă la un moment dat, în afara cazului în care restul deținătorilor de monezi ar dori să vândă acestei entități, chiar și cei mai bogați și determinați cumpărători nu ar putea să-i dețină pe toți.&lt;br /&gt;
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Adițional, noi bitcoini sunt creați zilnic și vor continua să fie creați în deceniile următoare. Rata la care aceștia sunt creați va scădea la valori insignifiante. Cei ce minează nu sunt obligați să-și vândă monedele, prin urmare nu toate acestea vor ajunge pe piețele valutare.&lt;br /&gt;
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Cu toate acestea, această situație nu sugerează că piețele nu sunt vulnerabile manipulărilor de preț. Nu este necesară o cantitate mare de bani pentru a determina creșterea sau scăderea de preț, prin urmare bitconii rămânând niște active volatile.&lt;br /&gt;
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=== Dacă cineva creează un nou lanț de blocuri (block chain), sau o nouă monedă digitală care scoate Bitcoinul din uz?===&lt;br /&gt;
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That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
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As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
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A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
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Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
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A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
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A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
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This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
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=== Este Bitcoin susceptibil manipulării valorii sale? ===&lt;br /&gt;
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Capitalizarea de piață a Bitcoin, în prezent la aflată la un nivel scăzut, este echivalentă cu faptul că orice investitor cu buzunarele suficient de adânci poate schimba/manipula semnificativ rata de schimb. Este aceasta o problemă?&lt;br /&gt;
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Este o problemă doar dacă dumneavoastră ați investi în monedă pentru o perioadă scurtă de timp.&lt;br /&gt;
Un manipulator nu-i poate schimba proprietățile fundamentale. Pe o perioadă de 5-10 ani, câștigul dumneavoastră total ar fi deasupra oricăror pierderi datorate manipulării pieței.&lt;br /&gt;
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== Efectuarea și primirea de plăți ==&lt;br /&gt;
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=== De ce trebuie să aștept 10 minute înainte să pot cheltui banii primiți? ===&lt;br /&gt;
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10 minute reprezintă intervalul mediu de timp necesar găsirii unui bloc. Acest interval poate fi semnificativ mai mic sau mai mare depinzând de şansă; 10 minute reprezintă timpul mediu. &lt;br /&gt;
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Puteţi vedea cât au durat toate tranzacţiile recente aici: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
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[[Blocurile]] (numite &amp;quot;confirmări&amp;quot; in GUI) reprezintă modul în care reţeaua Bitcoin ajunge la un consens referitor la cine şi ce anume deţine. Odată ce un bloc este găsit toată lumea este de acord că tu deţii acele monezi, deci le poţi cheltui din nou. Până atunci, este posibil ca unele noduri ale reţelei să creadă altceva, dacă cineva atentează să fraudeze sistemul printr-o încercare de a inversa o tranzacţie. Cu cât o tranzacţie are mai multe confirmări, cu atât mai mic este riscul unei astfel de tentative. Doar 6 blocuri sau 1 oră este îndeajuns pentru a face această tentativă de inversare a unei tranzacţii impractică din punct de vedere computaţional. Paralel, este o îmbunătăţire majoră faţă de actualele carduri de credit unde chargeback-urile pot apărea şi după trei luni de la tranzacţia iniţiala!&lt;br /&gt;
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Intervalul de zece minute a fost ales special de [[Satoshi Nakamoto]] ca un compromis între intervalul de propagare al noilor blocuri în reţelele mari şi puterea de calcul irosită din cauza scindărilor in blockchain. Pentru o explicaţie tehnică amănunţită, citiţi [http://www.bitcoin.org/bitcoin.pdf lucrarea tehnică originală] scrisă de [[Satoshi Nakamoto]].&lt;br /&gt;
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[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
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=== Trebuie să aştept că tranzacţiile mele să fie confirmate pentru a cumpăra sau vinde lucruri folosind Bitcoin? ===&lt;br /&gt;
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DA, trebuie, dacă tranzacţia este non-recourse(cu răspundere limitată). Software-ul de referinţă Bitcoin(clientul original conceput de [[Satoshi Nakamoto]]) nu marchează tranzacţiile ca fiind confirmate decât după ce au trecut 6 blocuri(confirmări). Pe măsură ce tranzacţiile ajung tot mai adânc în blockchain devin din ce în ce mai non-reversibile dar există riscul de a fi reversibile înainte de prima confirmare. Un număr de 2 până la 6 confirmări sunt recomandate pentru situaţii non-recourse depinzând de valoarea tranzacţiilor în cauză.&lt;br /&gt;
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De obicei cei care adresează această întrebare se referă la aplicaţii ca supermarketuri. Aceasta în general este o situaţie recourse(cu deplină incredere): dacă cineva încearcă să facă un double-spend(să cheltuiască aceiasi bani de două ori) într-o tranzacţie faţă în faţă s-ar putea să aibă succes de câteva ori, dar probabilistic vorbind una dintre aceste tentative va fi observată, iar penalizarea sau amenda va fi de ceva ori mai scumpă decât valoarea unei astfel de tentative. &lt;br /&gt;
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Cheltuirile duble ar putea reprezenta o problemă pentru un automat de sucuri aflat într-o zonă cu trafic scăzut şi fără camere de supraveghere în proximitate. Un astfel de automat nu ar trebui să onoreze plăti ce au 0 confirmări, şi ar trebui să folosească în schimb un alt mecanism pentru a valida astfel de tranzacţii, a se citi articolul [[Mituri#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|acesta]] pentru alternative.&lt;br /&gt;
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Aplicaţii ce necesită o procesare a plăţii imediată, că supermarketurile sau automatele de sucuri, trebuie să calculeze riscurile. Acesta este un exemplu de inversare a unei tranzacţii neconfirmate:&lt;br /&gt;
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Un [[Double-spending#Finney_attack|atac Finney]], în care atacatorul minează un bloc conţinând o mişcare de monezi către el însuşi. Îndată ce acesta găseşte soluţia blocului, se grăbeşte să facă o tranzacţie cu cineva, apoi emite blocul în reţea, astfel luându-şi monezile înapoi. Acest atac este un risc în principiu pentru bunurile ce sunt trimise imediat, cum ar fi bunuri virtuale ca descărcarea unor melodii sau schimburile valutare. Deoarece atacatorul nu poate alege timpul exact al atacului, acesta nu este un risc pentru supermarketuri de exemplu, unde atacatorul nu poate alege exact momentul plăţii(din cauza cozilor, etc). Atacul poate eşua dacă cineva găseşte un bloc conţinând tranzacţia respectivă înainte ca atacatorul să emită blocul său reţelei. Acesta este motivul pentru care comercianţii, pentru a diminua acest risc, cer clienţilor să aştepte un interval de timp mai mic decât o confirmare. &lt;br /&gt;
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Deoarece şansa de reuşită al acestui atac nu este chiar inexistentă, comercianţii ce doresc să vândă lucruri automat şi instant ar putea calcula în preţ şi acest risc de fraudă, sau să folosească o asigurare.&lt;br /&gt;
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=== Cineva mi-a trimis bitcoini şi nu au ajuns! Unde sunt? ===&lt;br /&gt;
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Nu te panica! Există un număr de motive pentru care bitcoinii tăi nu au apărut încă, şi un număr de metode pentru a diagnostica problema. &lt;br /&gt;
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În primul rând, dacă foloseşti clientul Bitcoin-Qt asigură-te că este sincronizat în totalitate. &lt;br /&gt;
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De asemenea, s-ar putea ca tranzacţia să nu fi fost inclusă încă într-un bloc. &lt;br /&gt;
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Tranzacţiile în desfăşurare(pending) se pot verifica accesând [http://blockchain.info here] şi căutând adresa respectivă. Dacă tranzacţia este listată acolo este doar o chestiune de timp până ce va fi inclusă într-un bloc şi să apară în client. &lt;br /&gt;
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Dacă tranzacţia include monezi ce au fost incluse într-o tranzacţie recentă este posibil să fie considerată o tranzacţie cu prioritate scăzută. De asemenea, tranzacţiile pot dura mai mult dacă taxa de tranzacţie nu a fost suficient de mare. Dacă nu există deloc o taxa inclusă, tranzacţia ar putea fi încadrată ca una de prioritate foarte scăzută şi poate dura ore sau chiar zile până va fi inclusă într-un bloc.&lt;br /&gt;
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=== De ce adresa mea de Bitcoin se schimbă? ===&lt;br /&gt;
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De fiecare dată când adresa afişată la &amp;quot;Your address&amp;quot; primeşte o tranzacţie, Bitcoin-Qt o înlocuieşte cu o nouă adresa. Acest lucru se produce pentru a încuraja utilizatorii să folosească o adresă nouă pentru fiecare tranzacţie, fapt ce îmbunătăţeşte [[anonimitatea]]. Toate adresele folosite înainte sunt încă folosibile: ele pot fi accesate în &amp;quot;&amp;quot;Settings -&amp;gt; Your Receiving Address&#039;&#039;.&lt;br /&gt;
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===How much will the transaction fee be?===&lt;br /&gt;
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Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
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The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
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A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
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Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
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As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
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=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
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Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
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If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
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=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
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The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
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In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
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When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
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If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
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==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
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Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
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If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
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=== How does the peer finding mechanism work? ===&lt;br /&gt;
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Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
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==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
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Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
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===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
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===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Ajutor==&lt;br /&gt;
===Aş vrea să aflu mai multe. Unde aş putea găsi mai multe informaţii?===&lt;br /&gt;
&lt;br /&gt;
* Citiţi [[Introducere|introducerea]]&lt;br /&gt;
* Citiţi şi postaţi pe [https://bitcointalk.org/index.php?board=108.0 Bitcointalk.org România]&lt;br /&gt;
* Accesaţi canalele [[:Bitcoin:Community_portal#IRC_Chat|IRC Bitcoin]]&lt;br /&gt;
* Vizitaţi şi daţi un Like paginii de Facebook [http://www.facebook.com/pages/Bitcoin-Romania/241044439366768 Bitcoin România]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=80</id>
		<title>Intrebari Frecvente</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=80"/>
		<updated>2013-05-24T08:18:58Z</updated>

		<summary type="html">&lt;p&gt;8fold: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;).&lt;br /&gt;
Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Adresă Bitcoin]]. &lt;br /&gt;
Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
There are a variety of ways to acquire bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Accept bitcoins as payment for goods or services.&lt;br /&gt;
* The most common way to buy bitcoins are the [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* There are several services where you can [[Buying_Bitcoins_(the_noob_version)|trade them]] for traditional currency.&lt;br /&gt;
* Find someone to trade cash for bitcoins in-person through a [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participate in a [[Pooled mining|mining pool]].&lt;br /&gt;
* If you have a lot of mining hardware, you can solo mine and attempt to create a new [[block]] (currently yields 25 bitcoins plus transaction fees).&lt;br /&gt;
* Visit sites that provide [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
=== Garantează Bitcoin un flux gratis de bani? ===&lt;br /&gt;
&lt;br /&gt;
Since Bitcoin is a new technology, what it is and how it works may be initially unclear.  Bitcoin is sometimes presented as being one of three things:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;Some sort of online &#039;get-rich-quick&#039; scam.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A loophole in the market economy, the installation of which guarantees a steady influx of cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A sure investment that will almost certainly yield a profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
In fact, none of the above are true.  Let&#039;s look at them independently.&lt;br /&gt;
&lt;br /&gt;
;Is Bitcoin a &#039;get-rich-quick&#039; scheme?&lt;br /&gt;
:If you&#039;ve spent much time on the Internet, you&#039;ve probably seen ads for many &#039;get-rich-quick&#039; schemes. These ads usually promise huge profits for a small amounts of easy work.  Such schemes are usually pyramid/matrix-style schemes that make money from their own employees and offer nothing of any real value.  Most convince one to buy packages that will make them earn hundreds a day, which in fact  have the buyer distribute more such ads, and make minute profits.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin is in no way similar to these schemes. Bitcoin doesn&#039;t promise windfall profits. There is no way for the developers to make money from your involvement or to take money from you. That bitcoins are nearly impossible to acquire without the owner&#039;s consent represents one of its greatest strengths.  Bitcoin is an experimental, virtual currency that may succeed or may fail. None of its developers expect to get rich off of it. &lt;br /&gt;
&lt;br /&gt;
:A more detailed answer to this question can be found [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
;Will I make money by installing the client?&lt;br /&gt;
:Most people who use Bitcoin don&#039;t earn anything by doing so, and the default client has no built-in way to earn Bitcoins.  A small minority of people with dedicated, high-performance hardware do earn some Bitcoins by &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generating new bitcoins, see [[#What is mining?|What is mining?]]) with special software, but joining Bitcoin shouldn&#039;t be construed as being the road to riches.  Most Bitcoin users get involved because they find the project conceptually interesting and don&#039;t earn anything by doing so.  This is also why you won&#039;t find much speculation about the political or economic repercussions of Bitcoin anywhere on this site: Bitcoin developers owe their dedication to the project&#039;s intellectual yieldings more than to those of a monetary nature.  Bitcoin is still taking its first baby steps; it may go on to do great things but right now it only has something to offer those chasing conceptually interesting projects or bleeding edge technology.&lt;br /&gt;
&lt;br /&gt;
;As an investment, is Bitcoin a sure thing?&lt;br /&gt;
:Bitcoin is a new and interesting electronic currency, the value of which is not backed by any single government or organization.  Like other currencies, it is worth something partly because people are willing to trade it for goods and services. Its exchange rate fluctuates continuously, and sometimes wildly. It lacks wide acceptance and is vulnerable to manipulation by parties with modest funding. Security incidents such as website and account compromise may trigger major sell-offs. Other fluctuations can build into positive feedback loops and cause much larger exchange rate fluctuations. Anyone who puts money into Bitcoin should understand the risk they are taking and consider it a high-risk currency. Later, as Bitcoin becomes better known and more widely accepted, it may stabilize, but for the time being it is unpredictable. Any investment in Bitcoin should be done carefully and with a clear plan to manage the risk.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpăra bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
It is possible to buy [[physical bitcoins]] with PayPal but it is otherwise difficult and/or expensive to do so for non-physical bitcoins, because of significant risk to the seller. &lt;br /&gt;
&lt;br /&gt;
While it is possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most exchanges do not allow funding through PayPal. This is due to repeated cases where someone pays for bitcoins with Paypal, receives their bitcoins, and then fraudulently complains to Paypal that they never received their purchase. PayPal often sides with the fraudulent buyer in this case, which means any seller needs to cover that risk with higher fees or refuse to accept PayPal altogether.&lt;br /&gt;
&lt;br /&gt;
Buying Bitcoins from individuals this way is still possible, but requires the seller to have some trust that the buyer will not file a claim with PayPal to reverse the payment.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot găsi un forum dedicat discuțiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Please visit the  [[Bitcoin:Community_portal#Bitcoin_Community_Forums_on_various_platforms|Community Portal]] for links to Bitcoin-related forums.&lt;br /&gt;
&lt;br /&gt;
=== Cum se creează noi bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]&lt;br /&gt;
New bitcoins are generated by the network through the process of &amp;quot;[[#What is mining?|&#039;&#039;mining&#039;&#039;]]&amp;quot;. In a process that is similar to a continuous raffle draw, mining nodes on the network are awarded bitcoins each time they find the solution to a certain mathematical problem (and thereby create a new [[block]]). Creating a block is a [[proof of work]] with a difficulty that varies with the overall strength of the network.  The reward for solving a block is [[Controlled Currency Supply|automatically adjusted]] so that roughly every four years of operation of the Bitcoin network, half the amount of bitcoins created in the prior 4 years are created. {{formatnum:10500000}} bitcoins were created in the first 4 (approx.) years from January 2009 to November 2012.  Every four years thereafter this amount halves, so it will be {{formatnum:5250000}} over years 4-8, {{formatnum:2625000}} over years 8-12, and so on. Thus the total number of bitcoins in existence will never exceed {{formatnum:21000000}}. See [[Controlled Currency Supply]].&lt;br /&gt;
&lt;br /&gt;
Blocks are [[Mining|mined]] every 10 minutes, on average and for the first four years ({{formatnum:210000}} blocks) each block included 50 new bitcoins.  As the amount of processing power directed at mining changes, the difficulty of creating new bitcoins changes.  This difficulty factor is calculated every 2016 blocks and is based upon the time taken to generate the previous 2016 blocks. See [[Mining]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numărul total de bitcoini la ora actuală?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Current count]. Also see [https://blockchain.info/charts/total-bitcoins Total bitcoins in circulation chart]&lt;br /&gt;
&lt;br /&gt;
The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first {{formatnum:210000}} blocks, 25 BTC for the next {{formatnum:210000}} blocks, then 12.5 BTC, 6.25 BTC and so on.&lt;br /&gt;
&lt;br /&gt;
=== Cât de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
A bitcoin can be divided down to 8 decimal places. Therefore, 0.00000001 BTC is the smallest amount that can be handled in a transaction. If necessary, the protocol and related software can be modified to handle even smaller amounts.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominările bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)&lt;br /&gt;
* 0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)&lt;br /&gt;
* 0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)&lt;br /&gt;
&lt;br /&gt;
The above follows the accepted international SI prefixes for hundredths, thousandths, and millionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won&#039;t be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as &amp;quot;cent&amp;quot;, &amp;quot;nickel&amp;quot;, &amp;quot;dime&amp;quot;, &amp;quot;pence&amp;quot;, &amp;quot;pound&amp;quot;, &amp;quot;kopek&amp;quot; and so on are to be discouraged; this is a worldwide currency.&lt;br /&gt;
&lt;br /&gt;
One exception is the &amp;quot;satoshi&amp;quot; which is smallest denomination currently possible &lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)&lt;br /&gt;
which is so named in honour of Satoshi Nakamoto, the pseudonym of the inventor of Bitcoin.&lt;br /&gt;
&lt;br /&gt;
For an overview of all defined units of Bitcoin (including less common and niche units), see [[Units]].&lt;br /&gt;
&lt;br /&gt;
Further discussion on this topic can be found on the forums here:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum funcționează înjumătățirea când numărul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Eventually the reward will go from 0.00000001 BTC to zero and no more bitcoins will be created.  &lt;br /&gt;
&lt;br /&gt;
The block reward calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by two and rounded down. The integer is equal to the value in BTC * 100,000,000 since internally in the reference client software, all Bitcoin balances and values are stored as unsigned integers.&lt;br /&gt;
&lt;br /&gt;
With an initial block reward of 50 BTC, it will take many 4-year periods for the block reward to reach zero.&lt;br /&gt;
&lt;br /&gt;
=== Cât timp va dura până vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
The last block that will generate coins will be block #6,929,999 which should be generated at or near the year 2140. The total number of coins in circulation will then remain static at 20,999,999.9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Even if the allowed precision is expanded from the current 8 decimals, the total BTC in circulation will always be slightly below 21 million (assuming everything else stays the same). For example, with 16 decimals of precision, the end total would be 20,999,999.999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Dacă nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Absolutely!  Even before the creation of coins ends, the use of [[transaction fee|transaction fees]] will likely make creating new blocks more valuable from the fees than the new coins being created.  When coin generation ends, these fees will sustain the ability to use bitcoins and the Bitcoin network. There is no practical limit on the number of blocks that will be mined in the future.&lt;br /&gt;
&lt;br /&gt;
=== Dar dacă nu mai sunt generate monezi, ce se întâmplă când se pierd bitcoini? Nu ar fi o problemă? ===&lt;br /&gt;
&lt;br /&gt;
Because of the law of supply and demand, when fewer bitcoins are available the ones that are left will be in higher demand, and therefore will have a higher value. So, as Bitcoins are lost, the remaining bitcoins will eventually increase in value to compensate. As the value of a bitcoin increases, the number of bitcoins required to purchase an item &#039;&#039;&#039;de&#039;&#039;&#039;creases. This is a [[Deflationary spiral|deflationary economic model]]. As the average transaction size reduces, transactions will probably be denominated in sub-units of a bitcoin such as millibitcoins (&amp;quot;Millies&amp;quot;) or microbitcoins (&amp;quot;Mikes&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
The Bitcoin protocol uses a base unit of one hundred-millionth of a Bitcoin (&amp;quot;a Satoshi&amp;quot;), but unused bits are available in the protocol fields that could be used to denote even smaller subdivisions.&lt;br /&gt;
&lt;br /&gt;
=== Dacă fiecare tranzacție este emisă prin rețea, atunci este Bitcoin scalabil? ===&lt;br /&gt;
The Bitcoin protocol allows lightweight clients that can use Bitcoin without downloading the entire transaction history. As traffic grows and this becomes more critical, implementations of the concept will be developed. Full network nodes will at some point become a more specialized service.&lt;br /&gt;
&lt;br /&gt;
With some modifications to the software, full Bitcoin nodes could easily keep up with both VISA and MasterCard combined, using only fairly modest hardware (a single high end server by todays standards). It is worth noting that the MasterCard network is structured somewhat like Bitcoin itself - as a peer to peer broadcast network.&lt;br /&gt;
&lt;br /&gt;
Learn more about [[Scalability]].&lt;br /&gt;
&lt;br /&gt;
== Economie ==&lt;br /&gt;
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===&lt;br /&gt;
Bitcoins have value because they are useful and because they are [[Controlled Currency Supply|scarce]]. As they are accepted by more merchants, their value will [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabilize]. See the [[Trade|list of Bitcoin-accepting sites]].&lt;br /&gt;
&lt;br /&gt;
When we say that a currency is backed up by gold, we mean that there&#039;s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.&lt;br /&gt;
&lt;br /&gt;
It&#039;s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn&#039;t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn&#039;t make anything valuable. For example, your fingerprints are scarce, but that doesn&#039;t mean they have any exchange value.&lt;br /&gt;
&lt;br /&gt;
Alternatively it needs to be added that while the law of supply and demand applies it does not guarantee value of Bitcoins in the future.  If confidence in Bitcoins is lost then it will not matter that the supply can no longer be increased, the demand will fall off with all holders trying to get rid of their coins.  An example of this can be seen in cases of state currencies, in cases when the state in question dissolves and so no new supply of the currency is available (the central authority managing the supply is gone), however the demand for the currency falls sharply because confidence in its purchasing power disappears.  Of-course Bitcoins do not have such central authority managing the supply of the coins, but it does not prevent confidence from eroding due to other situations that are not necessarily predictable.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
Yes, in the same way as the euro and dollar are. They only have value in exchange and have no inherent value. If everyone suddenly stopped accepting your dollars, euros or bitcoins, the &amp;quot;bubble&amp;quot; would burst and their value would drop to zero. But that is unlikely to happen: even in Somalia, where the government collapsed 20 years ago, [http://en.wikipedia.org/wiki/Somali_shilling Somali shillings] are still accepted as payment.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schemă piramidală/Ponzi? ===&lt;br /&gt;
In a Ponzi Scheme, the founders persuade investors that they’ll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.&lt;br /&gt;
&lt;br /&gt;
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.&lt;br /&gt;
&lt;br /&gt;
The fact that early adopters benefit more doesn&#039;t alone make anything a Ponzi scheme. All good investments in successful companies have this quality.&lt;br /&gt;
&lt;br /&gt;
=== Nu cumva Bitcoin favorizează pe nedrept investitorii inițiali? ===&lt;br /&gt;
Early adopters have a large number of bitcoins now because they took a risk and invested resources in an unproven technology. By so doing, they have helped Bitcoin become what it is now and what it will be in the future (hopefully, a ubiquitous decentralized digital currency). It is only fair they will reap the benefits of their successful investment.&lt;br /&gt;
&lt;br /&gt;
In any case, any bitcoin generated will probably change hands dozens of time as a medium of exchange, so the profit made from the initial distribution will be insignificant compared to the total commerce enabled by Bitcoin.&lt;br /&gt;
&lt;br /&gt;
Since the pricing of Bitcoins has fallen greatly from its June 2011 peak, prices today are much more similar to those enjoyed by many early adopters.  Those who are buying Bitcoins today likely believe that Bitcoin will grow significantly in the future.  Setting aside the brief opportunity to have sold Bitcoins at the June 2011 peak enjoyed by few, the early-adopter window is arguably still open.&lt;br /&gt;
&lt;br /&gt;
=== Pierderea de portofele și faptul că numărul de bitcoini este finit nu ar cauza deflație excesivă, distrugând Bitcoinul? ===&lt;br /&gt;
Worries about Bitcoin being destroyed by deflation are not entirely unfounded.  Unlike most currencies, which experience inflation as their founding institutions create more and more units, Bitcoin will likely experience gradual deflation with the passage of time.  Bitcoin is unique in that only a small amount of units will ever be produced (twenty-one million to be exact), this number has been known since the project&#039;s inception, and the units are created at a predictable rate.&lt;br /&gt;
&lt;br /&gt;
Also, Bitcoin users are faced with a danger that doesn&#039;t threaten users of any other currency: if a Bitcoin user loses his wallet, his money is gone forever, unless he finds it again. And not just to him; it&#039;s gone completely out of circulation, rendered utterly inaccessible to anyone. As people will lose their wallets, the total number of Bitcoins will slowly decrease.&lt;br /&gt;
&lt;br /&gt;
Therefore, Bitcoin seems to be faced with a unique problem. Whereas most currencies inflate over time, Bitcoin will mostly likely do just the opposite. Time will see the irretrievable loss of an ever-increasing number of Bitcoins. An already small number will be permanently whittled down further and further. And as there become fewer and fewer Bitcoins, the laws of supply and demand suggest that their value will probably continually rise.&lt;br /&gt;
&lt;br /&gt;
Thus Bitcoin is bound to once again stray into mysterious territory, because no one exactly knows what happens to a currency that grows continually more valuable. Many economists claim that a low level of inflation is a good thing for a currency, but nobody is quite sure about what might happens to one that continually deflates. Although deflation could hardly be called a rare phenomenon, steady, constant deflation is unheard of.  There may be a lot of speculation, no one has any hard data to back up their claims.&lt;br /&gt;
&lt;br /&gt;
That being said, there is a mechanism in place to combat the obvious consequences.  Extreme deflation would render most currencies highly impractical: if a single Canadian dollar could suddenly buy the holder a car, how would one go about buying bread or candy?  Even pennies would fetch more than a person could carry. Bitcoin, however, offers a simple and stylish solution: infinite divisibility.  Bitcoins can be divided up and trade into as small of pieces as one wants, so no matter how valuable Bitcoins become, one can trade them in practical quantities.  &lt;br /&gt;
&lt;br /&gt;
In fact, infinite divisibility should allow Bitcoins to function in cases of extreme wallet loss.  Even if, in the far future, so many people have lost their wallets that only a single Bitcoin, or a fraction of one, remains, Bitcoin should continue to function just fine. No one can claim to be sure what is going to happen, but deflation may prove to present a smaller threat than many expect.&lt;br /&gt;
&lt;br /&gt;
For more information, see the [[Deflationary spiral]] page.&lt;br /&gt;
&lt;br /&gt;
=== Dar dacă cineva ar cumpăra fiecare bitcoin existent? ===&lt;br /&gt;
Bitcoin markets are competitive -- meaning the price of a bitcoin will rise or fall depending on supply and demand at certain price levels.  Only a fraction of bitcoins issued to date are found on the exchange markets for sale.  So even though technically a buyer with lots of money could buy all the bitcoins offered for sale, unless those holding the rest of the bitcoins offer them for sale as well, even the wealthiest, most determined buyer can&#039;t get at them.&lt;br /&gt;
&lt;br /&gt;
Additionally, new currency continues to be issued daily and will continue to do so for decades though over time the rate at which they are issued declines to insignificant levels.  Those who are mining aren&#039;t obligated to sell their bitcoins so not all bitcoins will make it to the markets even.&lt;br /&gt;
&lt;br /&gt;
This situation doesn&#039;t suggest, however, that the markets aren&#039;t vulnerable to price manipulation.  It doesn&#039;t take significant amounts of money to move the market price up or down and thus Bitcoin remains a volatile asset.&lt;br /&gt;
&lt;br /&gt;
=== Dacă cineva creează un nou lanț de blocuri (block chain), sau o nouă monedă digitală care scoate Bitcoinul din uz?===&lt;br /&gt;
&lt;br /&gt;
That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
&lt;br /&gt;
As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
&lt;br /&gt;
A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
&lt;br /&gt;
Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
&lt;br /&gt;
A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
&lt;br /&gt;
A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
&lt;br /&gt;
This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin susceptibil manipulării valorii sale? ===&lt;br /&gt;
&lt;br /&gt;
The current low market cap of Bitcoin means that any investor with deep enough pockets can significantly change/manipulate the rate. Is this a problem?&lt;br /&gt;
&lt;br /&gt;
This is only a problem if you are investing in Bitcoin for short period of time. A manipulator can&#039;t change the fundamentals, and over a period of 5-10 years they will win over any short term manipulations.&lt;br /&gt;
&lt;br /&gt;
== Efectuarea și primirea de plăți ==&lt;br /&gt;
&lt;br /&gt;
=== De ce trebuie să aștept 10 minute înainte să pot cheltui banii primiți? ===&lt;br /&gt;
&lt;br /&gt;
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. &lt;br /&gt;
&lt;br /&gt;
You can see how long all other recent transactions have taken here: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
&lt;br /&gt;
[[Blocks]] (shown as &amp;quot;confirmations&amp;quot; in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it&#039;s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!&lt;br /&gt;
&lt;br /&gt;
Ten minutes was specifically chosen by [[Satoshi]] as a tradeoff between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. For a more technical explanation, see Satoshi&#039;s [http://www.bitcoin.org/bitcoin.pdf original technical paper].&lt;br /&gt;
&lt;br /&gt;
[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
&lt;br /&gt;
=== Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
YES, you do, IF the transaction is non-recourse. The Bitcoin reference software does not display transactions as confirmed until six blocks have passed (confirmations). As transactions are burred in the chain they become increasingly non-reversible but are very reversible before the first confirmation. Two to six confirmations are recommended for non-recourse situations depending on the value of the transactions involved.&lt;br /&gt;
&lt;br /&gt;
When people ask this question they are usually thinking about applications like supermarkets.  This generally is a recourse situation: if somebody tries to double-spend on a face-to-face transaction it might work a few times, but probabalistically speaking eventually one of the double-spends will get noticed, and the penalty for shoplifting charges in most localities is calibrated to be several times worse than the proceeds of a single shoplifting event.&lt;br /&gt;
&lt;br /&gt;
Double-spends might be a concern for something like a snack machine in a low-traffic area with no nearby security cameras.  Such a machine shouldn&#039;t honor 0-confirmation payments, and should instead use some other mechanism of clearing Bitcoin or validating transactions against reversal, see the wiki article [[Myths#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|here]] for alternatives.&lt;br /&gt;
&lt;br /&gt;
Applications that require immediate payment processing, like supermarkets or snack machines, need to manage the risks. Here is one way to reverse an unconfirmed payment:&lt;br /&gt;
&lt;br /&gt;
A [[Double-spending#Finney_attack|Finney attack]], in which an attacker mines a block containing a movement of some coins back to themselves. Once they find a block solution, they quickly go to a merchant and make a purchase, then broadcast the block, thus taking back the coins. This attack is a risk primarily for goods that are dispatched immediately, like song downloads or currency trades. Because the attacker can&#039;t choose the time of the attack, it isn&#039;t a risk for merchants such as supermarkets where you can&#039;t choose exactly when to pay (due to queues, etc). The attack can fail if somebody else finds a block containing the purchasing transaction before you release your own block, therefore, merchants can reduce but not eliminate the risk by making purchasers wait some length of time that&#039;s less than a confirm.&lt;br /&gt;
&lt;br /&gt;
Because pulling off this attack is not trivial, merchants who need to sell things automatically and instantly are most likely to just price the cost of reversal fraud in, or use insurance.&lt;br /&gt;
&lt;br /&gt;
=== I was sent some bitcoins and they haven&#039;t arrived yet! Where are they? ===&lt;br /&gt;
&lt;br /&gt;
Don&#039;t panic!  There are a number of reasons why your bitcoins might not show up yet, and a number of ways to diagnose them.  &lt;br /&gt;
&lt;br /&gt;
The latest version of the Bitcoin-Qt client tells you how far it has yet to go in downloading the blockchain.  Hover over the icon in the bottom right corner of the client to learn your client&#039;s status.&lt;br /&gt;
&lt;br /&gt;
If it has not caught up then it&#039;s possible that your transaction hasn&#039;t been included in a block yet.  &lt;br /&gt;
&lt;br /&gt;
You can check pending transactions in the network by going [http://blockchain.info here] and then searching for your address.  If the transaction is listed here then it&#039;s a matter of waiting until it gets included in a block before it will show in your client.  &lt;br /&gt;
&lt;br /&gt;
If the transaction is based on a coin that was in a recent transaction then it could be considered a low priority transaction. Transfers can take longer if the transaction fee paid was not high enough.  If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.&lt;br /&gt;
&lt;br /&gt;
=== Why does my Bitcoin address keep changing? ===&lt;br /&gt;
&lt;br /&gt;
Whenever the address listed in &amp;quot;Your address&amp;quot; receives a transaction, Bitcoin replaces it with a new address. This is meant to encourage you to use a new address for every transaction, which enhances [[anonymity]]. All of your old addresses are still usable: you can see them in &#039;&#039;Settings -&amp;gt; Your Receiving Addresses&#039;&#039;.&lt;br /&gt;
&lt;br /&gt;
===How much will the transaction fee be?===&lt;br /&gt;
&lt;br /&gt;
Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
&lt;br /&gt;
The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
&lt;br /&gt;
A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
&lt;br /&gt;
Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
&lt;br /&gt;
As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
&lt;br /&gt;
=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
&lt;br /&gt;
If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
&lt;br /&gt;
=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
&lt;br /&gt;
The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
&lt;br /&gt;
In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
&lt;br /&gt;
When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
&lt;br /&gt;
If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
&lt;br /&gt;
==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
&lt;br /&gt;
If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
&lt;br /&gt;
=== How does the peer finding mechanism work? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
&lt;br /&gt;
==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
&lt;br /&gt;
Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
&lt;br /&gt;
===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
&lt;br /&gt;
===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Help==&lt;br /&gt;
===I&#039;d like to learn more.  Where can I get help?===&lt;br /&gt;
&lt;br /&gt;
* Read the [[Introduction|introduction to bitcoin]] &lt;br /&gt;
* See the videos, podcasts, and blog posts from the [[Press]]&lt;br /&gt;
* Read and post on the [[:Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]&lt;br /&gt;
* Chat on one of the [[:Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels&lt;br /&gt;
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works&lt;br /&gt;
* Ask questions on the [http://bitcoin.stackexchange.com Bitcoin Stack Exchange]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=79</id>
		<title>Intrebari Frecvente</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=79"/>
		<updated>2013-05-24T07:51:51Z</updated>

		<summary type="html">&lt;p&gt;8fold: /* Unde pot gasi un forum dedicat discutiilor despre Bitcoin? */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;).&lt;br /&gt;
Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Adresă Bitcoin]]. &lt;br /&gt;
Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
There are a variety of ways to acquire bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Accept bitcoins as payment for goods or services.&lt;br /&gt;
* The most common way to buy bitcoins are the [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* There are several services where you can [[Buying_Bitcoins_(the_noob_version)|trade them]] for traditional currency.&lt;br /&gt;
* Find someone to trade cash for bitcoins in-person through a [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participate in a [[Pooled mining|mining pool]].&lt;br /&gt;
* If you have a lot of mining hardware, you can solo mine and attempt to create a new [[block]] (currently yields 25 bitcoins plus transaction fees).&lt;br /&gt;
* Visit sites that provide [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
===Garantează Bitcoin un flux gratis de bani?===&lt;br /&gt;
&lt;br /&gt;
Since Bitcoin is a new technology, what it is and how it works may be initially unclear.  Bitcoin is sometimes presented as being one of three things:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;Some sort of online &#039;get-rich-quick&#039; scam.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A loophole in the market economy, the installation of which guarantees a steady influx of cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A sure investment that will almost certainly yield a profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
In fact, none of the above are true.  Let&#039;s look at them independently.&lt;br /&gt;
&lt;br /&gt;
;Is Bitcoin a &#039;get-rich-quick&#039; scheme?&lt;br /&gt;
:If you&#039;ve spent much time on the Internet, you&#039;ve probably seen ads for many &#039;get-rich-quick&#039; schemes. These ads usually promise huge profits for a small amounts of easy work.  Such schemes are usually pyramid/matrix-style schemes that make money from their own employees and offer nothing of any real value.  Most convince one to buy packages that will make them earn hundreds a day, which in fact  have the buyer distribute more such ads, and make minute profits.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin is in no way similar to these schemes. Bitcoin doesn&#039;t promise windfall profits. There is no way for the developers to make money from your involvement or to take money from you. That bitcoins are nearly impossible to acquire without the owner&#039;s consent represents one of its greatest strengths.  Bitcoin is an experimental, virtual currency that may succeed or may fail. None of its developers expect to get rich off of it. &lt;br /&gt;
&lt;br /&gt;
:A more detailed answer to this question can be found [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
;Will I make money by installing the client?&lt;br /&gt;
:Most people who use Bitcoin don&#039;t earn anything by doing so, and the default client has no built-in way to earn Bitcoins.  A small minority of people with dedicated, high-performance hardware do earn some Bitcoins by &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generating new bitcoins, see [[#What is mining?|What is mining?]]) with special software, but joining Bitcoin shouldn&#039;t be construed as being the road to riches.  Most Bitcoin users get involved because they find the project conceptually interesting and don&#039;t earn anything by doing so.  This is also why you won&#039;t find much speculation about the political or economic repercussions of Bitcoin anywhere on this site: Bitcoin developers owe their dedication to the project&#039;s intellectual yieldings more than to those of a monetary nature.  Bitcoin is still taking its first baby steps; it may go on to do great things but right now it only has something to offer those chasing conceptually interesting projects or bleeding edge technology.&lt;br /&gt;
&lt;br /&gt;
;As an investment, is Bitcoin a sure thing?&lt;br /&gt;
:Bitcoin is a new and interesting electronic currency, the value of which is not backed by any single government or organization.  Like other currencies, it is worth something partly because people are willing to trade it for goods and services. Its exchange rate fluctuates continuously, and sometimes wildly. It lacks wide acceptance and is vulnerable to manipulation by parties with modest funding. Security incidents such as website and account compromise may trigger major sell-offs. Other fluctuations can build into positive feedback loops and cause much larger exchange rate fluctuations. Anyone who puts money into Bitcoin should understand the risk they are taking and consider it a high-risk currency. Later, as Bitcoin becomes better known and more widely accepted, it may stabilize, but for the time being it is unpredictable. Any investment in Bitcoin should be done carefully and with a clear plan to manage the risk.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpăra bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
It is possible to buy [[physical bitcoins]] with PayPal but it is otherwise difficult and/or expensive to do so for non-physical bitcoins, because of significant risk to the seller. &lt;br /&gt;
&lt;br /&gt;
While it is possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most exchanges do not allow funding through PayPal. This is due to repeated cases where someone pays for bitcoins with Paypal, receives their bitcoins, and then fraudulently complains to Paypal that they never received their purchase. PayPal often sides with the fraudulent buyer in this case, which means any seller needs to cover that risk with higher fees or refuse to accept PayPal altogether.&lt;br /&gt;
&lt;br /&gt;
Buying Bitcoins from individuals this way is still possible, but requires the seller to have some trust that the buyer will not file a claim with PayPal to reverse the payment.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot găsi un forum dedicat discuțiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Please visit the  [[Bitcoin:Community_portal#Bitcoin_Community_Forums_on_various_platforms|Community Portal]] for links to Bitcoin-related forums.&lt;br /&gt;
&lt;br /&gt;
=== Cum sunt bitcoinii creati? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]&lt;br /&gt;
New bitcoins are generated by the network through the process of &amp;quot;[[#What is mining?|&#039;&#039;mining&#039;&#039;]]&amp;quot;. In a process that is similar to a continuous raffle draw, mining nodes on the network are awarded bitcoins each time they find the solution to a certain mathematical problem (and thereby create a new [[block]]). Creating a block is a [[proof of work]] with a difficulty that varies with the overall strength of the network.  The reward for solving a block is [[Controlled Currency Supply|automatically adjusted]] so that roughly every four years of operation of the Bitcoin network, half the amount of bitcoins created in the prior 4 years are created. {{formatnum:10500000}} bitcoins were created in the first 4 (approx.) years from January 2009 to November 2012.  Every four years thereafter this amount halves, so it will be {{formatnum:5250000}} over years 4-8, {{formatnum:2625000}} over years 8-12, and so on. Thus the total number of bitcoins in existence will never exceed {{formatnum:21000000}}. See [[Controlled Currency Supply]].&lt;br /&gt;
&lt;br /&gt;
Blocks are [[Mining|mined]] every 10 minutes, on average and for the first four years ({{formatnum:210000}} blocks) each block included 50 new bitcoins.  As the amount of processing power directed at mining changes, the difficulty of creating new bitcoins changes.  This difficulty factor is calculated every 2016 blocks and is based upon the time taken to generate the previous 2016 blocks. See [[Mining]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numarul total de bitcoini?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Current count]. Also see [https://blockchain.info/charts/total-bitcoins Total bitcoins in circulation chart]&lt;br /&gt;
&lt;br /&gt;
The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first {{formatnum:210000}} blocks, 25 BTC for the next {{formatnum:210000}} blocks, then 12.5 BTC, 6.25 BTC and so on.&lt;br /&gt;
&lt;br /&gt;
=== Cat de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
A bitcoin can be divided down to 8 decimal places. Therefore, 0.00000001 BTC is the smallest amount that can be handled in a transaction. If necessary, the protocol and related software can be modified to handle even smaller amounts.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominarile bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)&lt;br /&gt;
* 0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)&lt;br /&gt;
* 0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)&lt;br /&gt;
&lt;br /&gt;
The above follows the accepted international SI prefixes for hundredths, thousandths, and millionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won&#039;t be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as &amp;quot;cent&amp;quot;, &amp;quot;nickel&amp;quot;, &amp;quot;dime&amp;quot;, &amp;quot;pence&amp;quot;, &amp;quot;pound&amp;quot;, &amp;quot;kopek&amp;quot; and so on are to be discouraged; this is a worldwide currency.&lt;br /&gt;
&lt;br /&gt;
One exception is the &amp;quot;satoshi&amp;quot; which is smallest denomination currently possible &lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)&lt;br /&gt;
which is so named in honour of Satoshi Nakamoto, the pseudonym of the inventor of Bitcoin.&lt;br /&gt;
&lt;br /&gt;
For an overview of all defined units of Bitcoin (including less common and niche units), see [[Units]].&lt;br /&gt;
&lt;br /&gt;
Further discussion on this topic can be found on the forums here:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum functioneaza injumatatirea cand numarul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Eventually the reward will go from 0.00000001 BTC to zero and no more bitcoins will be created.  &lt;br /&gt;
&lt;br /&gt;
The block reward calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by two and rounded down. The integer is equal to the value in BTC * 100,000,000 since internally in the reference client software, all Bitcoin balances and values are stored as unsigned integers.&lt;br /&gt;
&lt;br /&gt;
With an initial block reward of 50 BTC, it will take many 4-year periods for the block reward to reach zero.&lt;br /&gt;
&lt;br /&gt;
=== Cat timp va dura pana vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
The last block that will generate coins will be block #6,929,999 which should be generated at or near the year 2140. The total number of coins in circulation will then remain static at 20,999,999.9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Even if the allowed precision is expanded from the current 8 decimals, the total BTC in circulation will always be slightly below 21 million (assuming everything else stays the same). For example, with 16 decimals of precision, the end total would be 20,999,999.999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Daca nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Absolutely!  Even before the creation of coins ends, the use of [[transaction fee|transaction fees]] will likely make creating new blocks more valuable from the fees than the new coins being created.  When coin generation ends, these fees will sustain the ability to use bitcoins and the Bitcoin network. There is no practical limit on the number of blocks that will be mined in the future.&lt;br /&gt;
&lt;br /&gt;
=== Dar daca nu mai sunt generate monezi, ce se intampla cand se pierd bitcoini? Nu ar fi o problema? ===&lt;br /&gt;
&lt;br /&gt;
Because of the law of supply and demand, when fewer bitcoins are available the ones that are left will be in higher demand, and therefore will have a higher value. So, as Bitcoins are lost, the remaining bitcoins will eventually increase in value to compensate. As the value of a bitcoin increases, the number of bitcoins required to purchase an item &#039;&#039;&#039;de&#039;&#039;&#039;creases. This is a [[Deflationary spiral|deflationary economic model]]. As the average transaction size reduces, transactions will probably be denominated in sub-units of a bitcoin such as millibitcoins (&amp;quot;Millies&amp;quot;) or microbitcoins (&amp;quot;Mikes&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
The Bitcoin protocol uses a base unit of one hundred-millionth of a Bitcoin (&amp;quot;a Satoshi&amp;quot;), but unused bits are available in the protocol fields that could be used to denote even smaller subdivisions.&lt;br /&gt;
&lt;br /&gt;
=== Daca fiecare tranzactie este emisa prin retea, atunci Bitcoin este scalabil? ===&lt;br /&gt;
The Bitcoin protocol allows lightweight clients that can use Bitcoin without downloading the entire transaction history. As traffic grows and this becomes more critical, implementations of the concept will be developed. Full network nodes will at some point become a more specialized service.&lt;br /&gt;
&lt;br /&gt;
With some modifications to the software, full Bitcoin nodes could easily keep up with both VISA and MasterCard combined, using only fairly modest hardware (a single high end server by todays standards). It is worth noting that the MasterCard network is structured somewhat like Bitcoin itself - as a peer to peer broadcast network.&lt;br /&gt;
&lt;br /&gt;
Learn more about [[Scalability]].&lt;br /&gt;
&lt;br /&gt;
==Economie==&lt;br /&gt;
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===&lt;br /&gt;
Bitcoins have value because they are useful and because they are [[Controlled Currency Supply|scarce]]. As they are accepted by more merchants, their value will [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabilize]. See the [[Trade|list of Bitcoin-accepting sites]].&lt;br /&gt;
&lt;br /&gt;
When we say that a currency is backed up by gold, we mean that there&#039;s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.&lt;br /&gt;
&lt;br /&gt;
It&#039;s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn&#039;t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn&#039;t make anything valuable. For example, your fingerprints are scarce, but that doesn&#039;t mean they have any exchange value.&lt;br /&gt;
&lt;br /&gt;
Alternatively it needs to be added that while the law of supply and demand applies it does not guarantee value of Bitcoins in the future.  If confidence in Bitcoins is lost then it will not matter that the supply can no longer be increased, the demand will fall off with all holders trying to get rid of their coins.  An example of this can be seen in cases of state currencies, in cases when the state in question dissolves and so no new supply of the currency is available (the central authority managing the supply is gone), however the demand for the currency falls sharply because confidence in its purchasing power disappears.  Of-course Bitcoins do not have such central authority managing the supply of the coins, but it does not prevent confidence from eroding due to other situations that are not necessarily predictable.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
Yes, in the same way as the euro and dollar are. They only have value in exchange and have no inherent value. If everyone suddenly stopped accepting your dollars, euros or bitcoins, the &amp;quot;bubble&amp;quot; would burst and their value would drop to zero. But that is unlikely to happen: even in Somalia, where the government collapsed 20 years ago, [http://en.wikipedia.org/wiki/Somali_shilling Somali shillings] are still accepted as payment.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schema piramidala/Ponzi? ===&lt;br /&gt;
In a Ponzi Scheme, the founders persuade investors that they’ll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.&lt;br /&gt;
&lt;br /&gt;
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.&lt;br /&gt;
&lt;br /&gt;
The fact that early adopters benefit more doesn&#039;t alone make anything a Ponzi scheme. All good investments in successful companies have this quality.&lt;br /&gt;
&lt;br /&gt;
=== Nu cumva Bitcoin favorizeaza pe nedrept investitorii initiali? ===&lt;br /&gt;
Early adopters have a large number of bitcoins now because they took a risk and invested resources in an unproven technology. By so doing, they have helped Bitcoin become what it is now and what it will be in the future (hopefully, a ubiquitous decentralized digital currency). It is only fair they will reap the benefits of their successful investment.&lt;br /&gt;
&lt;br /&gt;
In any case, any bitcoin generated will probably change hands dozens of time as a medium of exchange, so the profit made from the initial distribution will be insignificant compared to the total commerce enabled by Bitcoin.&lt;br /&gt;
&lt;br /&gt;
Since the pricing of Bitcoins has fallen greatly from its June 2011 peak, prices today are much more similar to those enjoyed by many early adopters.  Those who are buying Bitcoins today likely believe that Bitcoin will grow significantly in the future.  Setting aside the brief opportunity to have sold Bitcoins at the June 2011 peak enjoyed by few, the early-adopter window is arguably still open.&lt;br /&gt;
&lt;br /&gt;
===Pierderea de portofele si faptul ca numarul de bitcoini este finit nu ar cauza deflatie excesiva, distrugand Bitcoinul? ===&lt;br /&gt;
Worries about Bitcoin being destroyed by deflation are not entirely unfounded.  Unlike most currencies, which experience inflation as their founding institutions create more and more units, Bitcoin will likely experience gradual deflation with the passage of time.  Bitcoin is unique in that only a small amount of units will ever be produced (twenty-one million to be exact), this number has been known since the project&#039;s inception, and the units are created at a predictable rate.&lt;br /&gt;
&lt;br /&gt;
Also, Bitcoin users are faced with a danger that doesn&#039;t threaten users of any other currency: if a Bitcoin user loses his wallet, his money is gone forever, unless he finds it again. And not just to him; it&#039;s gone completely out of circulation, rendered utterly inaccessible to anyone. As people will lose their wallets, the total number of Bitcoins will slowly decrease.&lt;br /&gt;
&lt;br /&gt;
Therefore, Bitcoin seems to be faced with a unique problem. Whereas most currencies inflate over time, Bitcoin will mostly likely do just the opposite. Time will see the irretrievable loss of an ever-increasing number of Bitcoins. An already small number will be permanently whittled down further and further. And as there become fewer and fewer Bitcoins, the laws of supply and demand suggest that their value will probably continually rise.&lt;br /&gt;
&lt;br /&gt;
Thus Bitcoin is bound to once again stray into mysterious territory, because no one exactly knows what happens to a currency that grows continually more valuable. Many economists claim that a low level of inflation is a good thing for a currency, but nobody is quite sure about what might happens to one that continually deflates. Although deflation could hardly be called a rare phenomenon, steady, constant deflation is unheard of.  There may be a lot of speculation, no one has any hard data to back up their claims.&lt;br /&gt;
&lt;br /&gt;
That being said, there is a mechanism in place to combat the obvious consequences.  Extreme deflation would render most currencies highly impractical: if a single Canadian dollar could suddenly buy the holder a car, how would one go about buying bread or candy?  Even pennies would fetch more than a person could carry. Bitcoin, however, offers a simple and stylish solution: infinite divisibility.  Bitcoins can be divided up and trade into as small of pieces as one wants, so no matter how valuable Bitcoins become, one can trade them in practical quantities.  &lt;br /&gt;
&lt;br /&gt;
In fact, infinite divisibility should allow Bitcoins to function in cases of extreme wallet loss.  Even if, in the far future, so many people have lost their wallets that only a single Bitcoin, or a fraction of one, remains, Bitcoin should continue to function just fine. No one can claim to be sure what is going to happen, but deflation may prove to present a smaller threat than many expect.&lt;br /&gt;
&lt;br /&gt;
For more information, see the [[Deflationary spiral]] page.&lt;br /&gt;
&lt;br /&gt;
=== Daca cineva ar cumpara fiecare bitcoin care a fost creat? ===&lt;br /&gt;
Bitcoin markets are competitive -- meaning the price of a bitcoin will rise or fall depending on supply and demand at certain price levels.  Only a fraction of bitcoins issued to date are found on the exchange markets for sale.  So even though technically a buyer with lots of money could buy all the bitcoins offered for sale, unless those holding the rest of the bitcoins offer them for sale as well, even the wealthiest, most determined buyer can&#039;t get at them.&lt;br /&gt;
&lt;br /&gt;
Additionally, new currency continues to be issued daily and will continue to do so for decades though over time the rate at which they are issued declines to insignificant levels.  Those who are mining aren&#039;t obligated to sell their bitcoins so not all bitcoins will make it to the markets even.&lt;br /&gt;
&lt;br /&gt;
This situation doesn&#039;t suggest, however, that the markets aren&#039;t vulnerable to price manipulation.  It doesn&#039;t take significant amounts of money to move the market price up or down and thus Bitcoin remains a volatile asset.&lt;br /&gt;
&lt;br /&gt;
===Daca cineva creaza un nou lant de blocuri(block chain), sau o noua moneda digitala care scoate Bitcoinul din uz?===&lt;br /&gt;
&lt;br /&gt;
That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
&lt;br /&gt;
As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
&lt;br /&gt;
A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
&lt;br /&gt;
Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
&lt;br /&gt;
A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
&lt;br /&gt;
A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
&lt;br /&gt;
This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoinul susceptibil manipularii valorii sale? ===&lt;br /&gt;
&lt;br /&gt;
The current low market cap of Bitcoin means that any investor with deep enough pockets can significantly change/manipulate the rate. Is this a problem?&lt;br /&gt;
&lt;br /&gt;
This is only a problem if you are investing in Bitcoin for short period of time. A manipulator can&#039;t change the fundamentals, and over a period of 5-10 years they will win over any short term manipulations.&lt;br /&gt;
&lt;br /&gt;
==Efectuarea si primirea de plati==&lt;br /&gt;
&lt;br /&gt;
=== De ce trebuie sa astept 10 minute inainte sa pot cheltui banii primiti? ===&lt;br /&gt;
&lt;br /&gt;
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. &lt;br /&gt;
&lt;br /&gt;
You can see how long all other recent transactions have taken here: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
&lt;br /&gt;
[[Blocks]] (shown as &amp;quot;confirmations&amp;quot; in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it&#039;s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!&lt;br /&gt;
&lt;br /&gt;
Ten minutes was specifically chosen by [[Satoshi]] as a tradeoff between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. For a more technical explanation, see Satoshi&#039;s [http://www.bitcoin.org/bitcoin.pdf original technical paper].&lt;br /&gt;
&lt;br /&gt;
[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
&lt;br /&gt;
=== Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
YES, you do, IF the transaction is non-recourse. The Bitcoin reference software does not display transactions as confirmed until six blocks have passed (confirmations). As transactions are burred in the chain they become increasingly non-reversible but are very reversible before the first confirmation. Two to six confirmations are recommended for non-recourse situations depending on the value of the transactions involved.&lt;br /&gt;
&lt;br /&gt;
When people ask this question they are usually thinking about applications like supermarkets.  This generally is a recourse situation: if somebody tries to double-spend on a face-to-face transaction it might work a few times, but probabalistically speaking eventually one of the double-spends will get noticed, and the penalty for shoplifting charges in most localities is calibrated to be several times worse than the proceeds of a single shoplifting event.&lt;br /&gt;
&lt;br /&gt;
Double-spends might be a concern for something like a snack machine in a low-traffic area with no nearby security cameras.  Such a machine shouldn&#039;t honor 0-confirmation payments, and should instead use some other mechanism of clearing Bitcoin or validating transactions against reversal, see the wiki article [[Myths#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|here]] for alternatives.&lt;br /&gt;
&lt;br /&gt;
Applications that require immediate payment processing, like supermarkets or snack machines, need to manage the risks. Here is one way to reverse an unconfirmed payment:&lt;br /&gt;
&lt;br /&gt;
A [[Double-spending#Finney_attack|Finney attack]], in which an attacker mines a block containing a movement of some coins back to themselves. Once they find a block solution, they quickly go to a merchant and make a purchase, then broadcast the block, thus taking back the coins. This attack is a risk primarily for goods that are dispatched immediately, like song downloads or currency trades. Because the attacker can&#039;t choose the time of the attack, it isn&#039;t a risk for merchants such as supermarkets where you can&#039;t choose exactly when to pay (due to queues, etc). The attack can fail if somebody else finds a block containing the purchasing transaction before you release your own block, therefore, merchants can reduce but not eliminate the risk by making purchasers wait some length of time that&#039;s less than a confirm.&lt;br /&gt;
&lt;br /&gt;
Because pulling off this attack is not trivial, merchants who need to sell things automatically and instantly are most likely to just price the cost of reversal fraud in, or use insurance.&lt;br /&gt;
&lt;br /&gt;
=== I was sent some bitcoins and they haven&#039;t arrived yet! Where are they? ===&lt;br /&gt;
&lt;br /&gt;
Don&#039;t panic!  There are a number of reasons why your bitcoins might not show up yet, and a number of ways to diagnose them.  &lt;br /&gt;
&lt;br /&gt;
The latest version of the Bitcoin-Qt client tells you how far it has yet to go in downloading the blockchain.  Hover over the icon in the bottom right corner of the client to learn your client&#039;s status.&lt;br /&gt;
&lt;br /&gt;
If it has not caught up then it&#039;s possible that your transaction hasn&#039;t been included in a block yet.  &lt;br /&gt;
&lt;br /&gt;
You can check pending transactions in the network by going [http://blockchain.info here] and then searching for your address.  If the transaction is listed here then it&#039;s a matter of waiting until it gets included in a block before it will show in your client.  &lt;br /&gt;
&lt;br /&gt;
If the transaction is based on a coin that was in a recent transaction then it could be considered a low priority transaction. Transfers can take longer if the transaction fee paid was not high enough.  If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.&lt;br /&gt;
&lt;br /&gt;
=== Why does my Bitcoin address keep changing? ===&lt;br /&gt;
&lt;br /&gt;
Whenever the address listed in &amp;quot;Your address&amp;quot; receives a transaction, Bitcoin replaces it with a new address. This is meant to encourage you to use a new address for every transaction, which enhances [[anonymity]]. All of your old addresses are still usable: you can see them in &#039;&#039;Settings -&amp;gt; Your Receiving Addresses&#039;&#039;.&lt;br /&gt;
&lt;br /&gt;
===How much will the transaction fee be?===&lt;br /&gt;
&lt;br /&gt;
Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
&lt;br /&gt;
The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
&lt;br /&gt;
A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
&lt;br /&gt;
Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
&lt;br /&gt;
As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
&lt;br /&gt;
=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
&lt;br /&gt;
If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
&lt;br /&gt;
=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
&lt;br /&gt;
The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
&lt;br /&gt;
In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
&lt;br /&gt;
When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
&lt;br /&gt;
If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
&lt;br /&gt;
==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
&lt;br /&gt;
If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
&lt;br /&gt;
=== How does the peer finding mechanism work? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
&lt;br /&gt;
==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
&lt;br /&gt;
Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
&lt;br /&gt;
===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
&lt;br /&gt;
===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Help==&lt;br /&gt;
===I&#039;d like to learn more.  Where can I get help?===&lt;br /&gt;
&lt;br /&gt;
* Read the [[Introduction|introduction to bitcoin]] &lt;br /&gt;
* See the videos, podcasts, and blog posts from the [[Press]]&lt;br /&gt;
* Read and post on the [[:Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]&lt;br /&gt;
* Chat on one of the [[:Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels&lt;br /&gt;
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works&lt;br /&gt;
* Ask questions on the [http://bitcoin.stackexchange.com Bitcoin Stack Exchange]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=78</id>
		<title>Intrebari Frecvente</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=78"/>
		<updated>2013-05-24T07:48:54Z</updated>

		<summary type="html">&lt;p&gt;8fold: /* Pot cumpara bitcoini cu Paypal? */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;).&lt;br /&gt;
Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Adresă Bitcoin]]. &lt;br /&gt;
Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
There are a variety of ways to acquire bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Accept bitcoins as payment for goods or services.&lt;br /&gt;
* The most common way to buy bitcoins are the [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* There are several services where you can [[Buying_Bitcoins_(the_noob_version)|trade them]] for traditional currency.&lt;br /&gt;
* Find someone to trade cash for bitcoins in-person through a [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participate in a [[Pooled mining|mining pool]].&lt;br /&gt;
* If you have a lot of mining hardware, you can solo mine and attempt to create a new [[block]] (currently yields 25 bitcoins plus transaction fees).&lt;br /&gt;
* Visit sites that provide [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
===Garantează Bitcoin un flux gratis de bani?===&lt;br /&gt;
&lt;br /&gt;
Since Bitcoin is a new technology, what it is and how it works may be initially unclear.  Bitcoin is sometimes presented as being one of three things:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;Some sort of online &#039;get-rich-quick&#039; scam.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A loophole in the market economy, the installation of which guarantees a steady influx of cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A sure investment that will almost certainly yield a profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
In fact, none of the above are true.  Let&#039;s look at them independently.&lt;br /&gt;
&lt;br /&gt;
;Is Bitcoin a &#039;get-rich-quick&#039; scheme?&lt;br /&gt;
:If you&#039;ve spent much time on the Internet, you&#039;ve probably seen ads for many &#039;get-rich-quick&#039; schemes. These ads usually promise huge profits for a small amounts of easy work.  Such schemes are usually pyramid/matrix-style schemes that make money from their own employees and offer nothing of any real value.  Most convince one to buy packages that will make them earn hundreds a day, which in fact  have the buyer distribute more such ads, and make minute profits.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin is in no way similar to these schemes. Bitcoin doesn&#039;t promise windfall profits. There is no way for the developers to make money from your involvement or to take money from you. That bitcoins are nearly impossible to acquire without the owner&#039;s consent represents one of its greatest strengths.  Bitcoin is an experimental, virtual currency that may succeed or may fail. None of its developers expect to get rich off of it. &lt;br /&gt;
&lt;br /&gt;
:A more detailed answer to this question can be found [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
;Will I make money by installing the client?&lt;br /&gt;
:Most people who use Bitcoin don&#039;t earn anything by doing so, and the default client has no built-in way to earn Bitcoins.  A small minority of people with dedicated, high-performance hardware do earn some Bitcoins by &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generating new bitcoins, see [[#What is mining?|What is mining?]]) with special software, but joining Bitcoin shouldn&#039;t be construed as being the road to riches.  Most Bitcoin users get involved because they find the project conceptually interesting and don&#039;t earn anything by doing so.  This is also why you won&#039;t find much speculation about the political or economic repercussions of Bitcoin anywhere on this site: Bitcoin developers owe their dedication to the project&#039;s intellectual yieldings more than to those of a monetary nature.  Bitcoin is still taking its first baby steps; it may go on to do great things but right now it only has something to offer those chasing conceptually interesting projects or bleeding edge technology.&lt;br /&gt;
&lt;br /&gt;
;As an investment, is Bitcoin a sure thing?&lt;br /&gt;
:Bitcoin is a new and interesting electronic currency, the value of which is not backed by any single government or organization.  Like other currencies, it is worth something partly because people are willing to trade it for goods and services. Its exchange rate fluctuates continuously, and sometimes wildly. It lacks wide acceptance and is vulnerable to manipulation by parties with modest funding. Security incidents such as website and account compromise may trigger major sell-offs. Other fluctuations can build into positive feedback loops and cause much larger exchange rate fluctuations. Anyone who puts money into Bitcoin should understand the risk they are taking and consider it a high-risk currency. Later, as Bitcoin becomes better known and more widely accepted, it may stabilize, but for the time being it is unpredictable. Any investment in Bitcoin should be done carefully and with a clear plan to manage the risk.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpăra bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
It is possible to buy [[physical bitcoins]] with PayPal but it is otherwise difficult and/or expensive to do so for non-physical bitcoins, because of significant risk to the seller. &lt;br /&gt;
&lt;br /&gt;
While it is possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most exchanges do not allow funding through PayPal. This is due to repeated cases where someone pays for bitcoins with Paypal, receives their bitcoins, and then fraudulently complains to Paypal that they never received their purchase. PayPal often sides with the fraudulent buyer in this case, which means any seller needs to cover that risk with higher fees or refuse to accept PayPal altogether.&lt;br /&gt;
&lt;br /&gt;
Buying Bitcoins from individuals this way is still possible, but requires the seller to have some trust that the buyer will not file a claim with PayPal to reverse the payment.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot gasi un forum dedicat discutiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Please visit the  [[Bitcoin:Community_portal#Bitcoin_Community_Forums_on_various_platforms|Community Portal]] for links to Bitcoin-related forums.&lt;br /&gt;
&lt;br /&gt;
=== Cum sunt bitcoinii creati? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]&lt;br /&gt;
New bitcoins are generated by the network through the process of &amp;quot;[[#What is mining?|&#039;&#039;mining&#039;&#039;]]&amp;quot;. In a process that is similar to a continuous raffle draw, mining nodes on the network are awarded bitcoins each time they find the solution to a certain mathematical problem (and thereby create a new [[block]]). Creating a block is a [[proof of work]] with a difficulty that varies with the overall strength of the network.  The reward for solving a block is [[Controlled Currency Supply|automatically adjusted]] so that roughly every four years of operation of the Bitcoin network, half the amount of bitcoins created in the prior 4 years are created. {{formatnum:10500000}} bitcoins were created in the first 4 (approx.) years from January 2009 to November 2012.  Every four years thereafter this amount halves, so it will be {{formatnum:5250000}} over years 4-8, {{formatnum:2625000}} over years 8-12, and so on. Thus the total number of bitcoins in existence will never exceed {{formatnum:21000000}}. See [[Controlled Currency Supply]].&lt;br /&gt;
&lt;br /&gt;
Blocks are [[Mining|mined]] every 10 minutes, on average and for the first four years ({{formatnum:210000}} blocks) each block included 50 new bitcoins.  As the amount of processing power directed at mining changes, the difficulty of creating new bitcoins changes.  This difficulty factor is calculated every 2016 blocks and is based upon the time taken to generate the previous 2016 blocks. See [[Mining]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numarul total de bitcoini?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Current count]. Also see [https://blockchain.info/charts/total-bitcoins Total bitcoins in circulation chart]&lt;br /&gt;
&lt;br /&gt;
The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first {{formatnum:210000}} blocks, 25 BTC for the next {{formatnum:210000}} blocks, then 12.5 BTC, 6.25 BTC and so on.&lt;br /&gt;
&lt;br /&gt;
=== Cat de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
A bitcoin can be divided down to 8 decimal places. Therefore, 0.00000001 BTC is the smallest amount that can be handled in a transaction. If necessary, the protocol and related software can be modified to handle even smaller amounts.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominarile bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)&lt;br /&gt;
* 0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)&lt;br /&gt;
* 0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)&lt;br /&gt;
&lt;br /&gt;
The above follows the accepted international SI prefixes for hundredths, thousandths, and millionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won&#039;t be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as &amp;quot;cent&amp;quot;, &amp;quot;nickel&amp;quot;, &amp;quot;dime&amp;quot;, &amp;quot;pence&amp;quot;, &amp;quot;pound&amp;quot;, &amp;quot;kopek&amp;quot; and so on are to be discouraged; this is a worldwide currency.&lt;br /&gt;
&lt;br /&gt;
One exception is the &amp;quot;satoshi&amp;quot; which is smallest denomination currently possible &lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)&lt;br /&gt;
which is so named in honour of Satoshi Nakamoto, the pseudonym of the inventor of Bitcoin.&lt;br /&gt;
&lt;br /&gt;
For an overview of all defined units of Bitcoin (including less common and niche units), see [[Units]].&lt;br /&gt;
&lt;br /&gt;
Further discussion on this topic can be found on the forums here:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum functioneaza injumatatirea cand numarul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Eventually the reward will go from 0.00000001 BTC to zero and no more bitcoins will be created.  &lt;br /&gt;
&lt;br /&gt;
The block reward calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by two and rounded down. The integer is equal to the value in BTC * 100,000,000 since internally in the reference client software, all Bitcoin balances and values are stored as unsigned integers.&lt;br /&gt;
&lt;br /&gt;
With an initial block reward of 50 BTC, it will take many 4-year periods for the block reward to reach zero.&lt;br /&gt;
&lt;br /&gt;
=== Cat timp va dura pana vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
The last block that will generate coins will be block #6,929,999 which should be generated at or near the year 2140. The total number of coins in circulation will then remain static at 20,999,999.9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Even if the allowed precision is expanded from the current 8 decimals, the total BTC in circulation will always be slightly below 21 million (assuming everything else stays the same). For example, with 16 decimals of precision, the end total would be 20,999,999.999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Daca nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Absolutely!  Even before the creation of coins ends, the use of [[transaction fee|transaction fees]] will likely make creating new blocks more valuable from the fees than the new coins being created.  When coin generation ends, these fees will sustain the ability to use bitcoins and the Bitcoin network. There is no practical limit on the number of blocks that will be mined in the future.&lt;br /&gt;
&lt;br /&gt;
=== Dar daca nu mai sunt generate monezi, ce se intampla cand se pierd bitcoini? Nu ar fi o problema? ===&lt;br /&gt;
&lt;br /&gt;
Because of the law of supply and demand, when fewer bitcoins are available the ones that are left will be in higher demand, and therefore will have a higher value. So, as Bitcoins are lost, the remaining bitcoins will eventually increase in value to compensate. As the value of a bitcoin increases, the number of bitcoins required to purchase an item &#039;&#039;&#039;de&#039;&#039;&#039;creases. This is a [[Deflationary spiral|deflationary economic model]]. As the average transaction size reduces, transactions will probably be denominated in sub-units of a bitcoin such as millibitcoins (&amp;quot;Millies&amp;quot;) or microbitcoins (&amp;quot;Mikes&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
The Bitcoin protocol uses a base unit of one hundred-millionth of a Bitcoin (&amp;quot;a Satoshi&amp;quot;), but unused bits are available in the protocol fields that could be used to denote even smaller subdivisions.&lt;br /&gt;
&lt;br /&gt;
=== Daca fiecare tranzactie este emisa prin retea, atunci Bitcoin este scalabil? ===&lt;br /&gt;
The Bitcoin protocol allows lightweight clients that can use Bitcoin without downloading the entire transaction history. As traffic grows and this becomes more critical, implementations of the concept will be developed. Full network nodes will at some point become a more specialized service.&lt;br /&gt;
&lt;br /&gt;
With some modifications to the software, full Bitcoin nodes could easily keep up with both VISA and MasterCard combined, using only fairly modest hardware (a single high end server by todays standards). It is worth noting that the MasterCard network is structured somewhat like Bitcoin itself - as a peer to peer broadcast network.&lt;br /&gt;
&lt;br /&gt;
Learn more about [[Scalability]].&lt;br /&gt;
&lt;br /&gt;
==Economie==&lt;br /&gt;
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===&lt;br /&gt;
Bitcoins have value because they are useful and because they are [[Controlled Currency Supply|scarce]]. As they are accepted by more merchants, their value will [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabilize]. See the [[Trade|list of Bitcoin-accepting sites]].&lt;br /&gt;
&lt;br /&gt;
When we say that a currency is backed up by gold, we mean that there&#039;s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.&lt;br /&gt;
&lt;br /&gt;
It&#039;s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn&#039;t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn&#039;t make anything valuable. For example, your fingerprints are scarce, but that doesn&#039;t mean they have any exchange value.&lt;br /&gt;
&lt;br /&gt;
Alternatively it needs to be added that while the law of supply and demand applies it does not guarantee value of Bitcoins in the future.  If confidence in Bitcoins is lost then it will not matter that the supply can no longer be increased, the demand will fall off with all holders trying to get rid of their coins.  An example of this can be seen in cases of state currencies, in cases when the state in question dissolves and so no new supply of the currency is available (the central authority managing the supply is gone), however the demand for the currency falls sharply because confidence in its purchasing power disappears.  Of-course Bitcoins do not have such central authority managing the supply of the coins, but it does not prevent confidence from eroding due to other situations that are not necessarily predictable.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
Yes, in the same way as the euro and dollar are. They only have value in exchange and have no inherent value. If everyone suddenly stopped accepting your dollars, euros or bitcoins, the &amp;quot;bubble&amp;quot; would burst and their value would drop to zero. But that is unlikely to happen: even in Somalia, where the government collapsed 20 years ago, [http://en.wikipedia.org/wiki/Somali_shilling Somali shillings] are still accepted as payment.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schema piramidala/Ponzi? ===&lt;br /&gt;
In a Ponzi Scheme, the founders persuade investors that they’ll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.&lt;br /&gt;
&lt;br /&gt;
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.&lt;br /&gt;
&lt;br /&gt;
The fact that early adopters benefit more doesn&#039;t alone make anything a Ponzi scheme. All good investments in successful companies have this quality.&lt;br /&gt;
&lt;br /&gt;
=== Nu cumva Bitcoin favorizeaza pe nedrept investitorii initiali? ===&lt;br /&gt;
Early adopters have a large number of bitcoins now because they took a risk and invested resources in an unproven technology. By so doing, they have helped Bitcoin become what it is now and what it will be in the future (hopefully, a ubiquitous decentralized digital currency). It is only fair they will reap the benefits of their successful investment.&lt;br /&gt;
&lt;br /&gt;
In any case, any bitcoin generated will probably change hands dozens of time as a medium of exchange, so the profit made from the initial distribution will be insignificant compared to the total commerce enabled by Bitcoin.&lt;br /&gt;
&lt;br /&gt;
Since the pricing of Bitcoins has fallen greatly from its June 2011 peak, prices today are much more similar to those enjoyed by many early adopters.  Those who are buying Bitcoins today likely believe that Bitcoin will grow significantly in the future.  Setting aside the brief opportunity to have sold Bitcoins at the June 2011 peak enjoyed by few, the early-adopter window is arguably still open.&lt;br /&gt;
&lt;br /&gt;
===Pierderea de portofele si faptul ca numarul de bitcoini este finit nu ar cauza deflatie excesiva, distrugand Bitcoinul? ===&lt;br /&gt;
Worries about Bitcoin being destroyed by deflation are not entirely unfounded.  Unlike most currencies, which experience inflation as their founding institutions create more and more units, Bitcoin will likely experience gradual deflation with the passage of time.  Bitcoin is unique in that only a small amount of units will ever be produced (twenty-one million to be exact), this number has been known since the project&#039;s inception, and the units are created at a predictable rate.&lt;br /&gt;
&lt;br /&gt;
Also, Bitcoin users are faced with a danger that doesn&#039;t threaten users of any other currency: if a Bitcoin user loses his wallet, his money is gone forever, unless he finds it again. And not just to him; it&#039;s gone completely out of circulation, rendered utterly inaccessible to anyone. As people will lose their wallets, the total number of Bitcoins will slowly decrease.&lt;br /&gt;
&lt;br /&gt;
Therefore, Bitcoin seems to be faced with a unique problem. Whereas most currencies inflate over time, Bitcoin will mostly likely do just the opposite. Time will see the irretrievable loss of an ever-increasing number of Bitcoins. An already small number will be permanently whittled down further and further. And as there become fewer and fewer Bitcoins, the laws of supply and demand suggest that their value will probably continually rise.&lt;br /&gt;
&lt;br /&gt;
Thus Bitcoin is bound to once again stray into mysterious territory, because no one exactly knows what happens to a currency that grows continually more valuable. Many economists claim that a low level of inflation is a good thing for a currency, but nobody is quite sure about what might happens to one that continually deflates. Although deflation could hardly be called a rare phenomenon, steady, constant deflation is unheard of.  There may be a lot of speculation, no one has any hard data to back up their claims.&lt;br /&gt;
&lt;br /&gt;
That being said, there is a mechanism in place to combat the obvious consequences.  Extreme deflation would render most currencies highly impractical: if a single Canadian dollar could suddenly buy the holder a car, how would one go about buying bread or candy?  Even pennies would fetch more than a person could carry. Bitcoin, however, offers a simple and stylish solution: infinite divisibility.  Bitcoins can be divided up and trade into as small of pieces as one wants, so no matter how valuable Bitcoins become, one can trade them in practical quantities.  &lt;br /&gt;
&lt;br /&gt;
In fact, infinite divisibility should allow Bitcoins to function in cases of extreme wallet loss.  Even if, in the far future, so many people have lost their wallets that only a single Bitcoin, or a fraction of one, remains, Bitcoin should continue to function just fine. No one can claim to be sure what is going to happen, but deflation may prove to present a smaller threat than many expect.&lt;br /&gt;
&lt;br /&gt;
For more information, see the [[Deflationary spiral]] page.&lt;br /&gt;
&lt;br /&gt;
=== Daca cineva ar cumpara fiecare bitcoin care a fost creat? ===&lt;br /&gt;
Bitcoin markets are competitive -- meaning the price of a bitcoin will rise or fall depending on supply and demand at certain price levels.  Only a fraction of bitcoins issued to date are found on the exchange markets for sale.  So even though technically a buyer with lots of money could buy all the bitcoins offered for sale, unless those holding the rest of the bitcoins offer them for sale as well, even the wealthiest, most determined buyer can&#039;t get at them.&lt;br /&gt;
&lt;br /&gt;
Additionally, new currency continues to be issued daily and will continue to do so for decades though over time the rate at which they are issued declines to insignificant levels.  Those who are mining aren&#039;t obligated to sell their bitcoins so not all bitcoins will make it to the markets even.&lt;br /&gt;
&lt;br /&gt;
This situation doesn&#039;t suggest, however, that the markets aren&#039;t vulnerable to price manipulation.  It doesn&#039;t take significant amounts of money to move the market price up or down and thus Bitcoin remains a volatile asset.&lt;br /&gt;
&lt;br /&gt;
===Daca cineva creaza un nou lant de blocuri(block chain), sau o noua moneda digitala care scoate Bitcoinul din uz?===&lt;br /&gt;
&lt;br /&gt;
That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
&lt;br /&gt;
As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
&lt;br /&gt;
A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
&lt;br /&gt;
Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
&lt;br /&gt;
A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
&lt;br /&gt;
A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
&lt;br /&gt;
This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoinul susceptibil manipularii valorii sale? ===&lt;br /&gt;
&lt;br /&gt;
The current low market cap of Bitcoin means that any investor with deep enough pockets can significantly change/manipulate the rate. Is this a problem?&lt;br /&gt;
&lt;br /&gt;
This is only a problem if you are investing in Bitcoin for short period of time. A manipulator can&#039;t change the fundamentals, and over a period of 5-10 years they will win over any short term manipulations.&lt;br /&gt;
&lt;br /&gt;
==Efectuarea si primirea de plati==&lt;br /&gt;
&lt;br /&gt;
=== De ce trebuie sa astept 10 minute inainte sa pot cheltui banii primiti? ===&lt;br /&gt;
&lt;br /&gt;
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. &lt;br /&gt;
&lt;br /&gt;
You can see how long all other recent transactions have taken here: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
&lt;br /&gt;
[[Blocks]] (shown as &amp;quot;confirmations&amp;quot; in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it&#039;s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!&lt;br /&gt;
&lt;br /&gt;
Ten minutes was specifically chosen by [[Satoshi]] as a tradeoff between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. For a more technical explanation, see Satoshi&#039;s [http://www.bitcoin.org/bitcoin.pdf original technical paper].&lt;br /&gt;
&lt;br /&gt;
[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
&lt;br /&gt;
=== Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
YES, you do, IF the transaction is non-recourse. The Bitcoin reference software does not display transactions as confirmed until six blocks have passed (confirmations). As transactions are burred in the chain they become increasingly non-reversible but are very reversible before the first confirmation. Two to six confirmations are recommended for non-recourse situations depending on the value of the transactions involved.&lt;br /&gt;
&lt;br /&gt;
When people ask this question they are usually thinking about applications like supermarkets.  This generally is a recourse situation: if somebody tries to double-spend on a face-to-face transaction it might work a few times, but probabalistically speaking eventually one of the double-spends will get noticed, and the penalty for shoplifting charges in most localities is calibrated to be several times worse than the proceeds of a single shoplifting event.&lt;br /&gt;
&lt;br /&gt;
Double-spends might be a concern for something like a snack machine in a low-traffic area with no nearby security cameras.  Such a machine shouldn&#039;t honor 0-confirmation payments, and should instead use some other mechanism of clearing Bitcoin or validating transactions against reversal, see the wiki article [[Myths#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|here]] for alternatives.&lt;br /&gt;
&lt;br /&gt;
Applications that require immediate payment processing, like supermarkets or snack machines, need to manage the risks. Here is one way to reverse an unconfirmed payment:&lt;br /&gt;
&lt;br /&gt;
A [[Double-spending#Finney_attack|Finney attack]], in which an attacker mines a block containing a movement of some coins back to themselves. Once they find a block solution, they quickly go to a merchant and make a purchase, then broadcast the block, thus taking back the coins. This attack is a risk primarily for goods that are dispatched immediately, like song downloads or currency trades. Because the attacker can&#039;t choose the time of the attack, it isn&#039;t a risk for merchants such as supermarkets where you can&#039;t choose exactly when to pay (due to queues, etc). The attack can fail if somebody else finds a block containing the purchasing transaction before you release your own block, therefore, merchants can reduce but not eliminate the risk by making purchasers wait some length of time that&#039;s less than a confirm.&lt;br /&gt;
&lt;br /&gt;
Because pulling off this attack is not trivial, merchants who need to sell things automatically and instantly are most likely to just price the cost of reversal fraud in, or use insurance.&lt;br /&gt;
&lt;br /&gt;
=== I was sent some bitcoins and they haven&#039;t arrived yet! Where are they? ===&lt;br /&gt;
&lt;br /&gt;
Don&#039;t panic!  There are a number of reasons why your bitcoins might not show up yet, and a number of ways to diagnose them.  &lt;br /&gt;
&lt;br /&gt;
The latest version of the Bitcoin-Qt client tells you how far it has yet to go in downloading the blockchain.  Hover over the icon in the bottom right corner of the client to learn your client&#039;s status.&lt;br /&gt;
&lt;br /&gt;
If it has not caught up then it&#039;s possible that your transaction hasn&#039;t been included in a block yet.  &lt;br /&gt;
&lt;br /&gt;
You can check pending transactions in the network by going [http://blockchain.info here] and then searching for your address.  If the transaction is listed here then it&#039;s a matter of waiting until it gets included in a block before it will show in your client.  &lt;br /&gt;
&lt;br /&gt;
If the transaction is based on a coin that was in a recent transaction then it could be considered a low priority transaction. Transfers can take longer if the transaction fee paid was not high enough.  If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.&lt;br /&gt;
&lt;br /&gt;
=== Why does my Bitcoin address keep changing? ===&lt;br /&gt;
&lt;br /&gt;
Whenever the address listed in &amp;quot;Your address&amp;quot; receives a transaction, Bitcoin replaces it with a new address. This is meant to encourage you to use a new address for every transaction, which enhances [[anonymity]]. All of your old addresses are still usable: you can see them in &#039;&#039;Settings -&amp;gt; Your Receiving Addresses&#039;&#039;.&lt;br /&gt;
&lt;br /&gt;
===How much will the transaction fee be?===&lt;br /&gt;
&lt;br /&gt;
Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
&lt;br /&gt;
The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
&lt;br /&gt;
A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
&lt;br /&gt;
Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
&lt;br /&gt;
As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
&lt;br /&gt;
=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
&lt;br /&gt;
If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
&lt;br /&gt;
=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
&lt;br /&gt;
The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
&lt;br /&gt;
In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
&lt;br /&gt;
When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
&lt;br /&gt;
If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
&lt;br /&gt;
==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
&lt;br /&gt;
If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
&lt;br /&gt;
=== How does the peer finding mechanism work? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
&lt;br /&gt;
==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
&lt;br /&gt;
Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
&lt;br /&gt;
===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
&lt;br /&gt;
===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Help==&lt;br /&gt;
===I&#039;d like to learn more.  Where can I get help?===&lt;br /&gt;
&lt;br /&gt;
* Read the [[Introduction|introduction to bitcoin]] &lt;br /&gt;
* See the videos, podcasts, and blog posts from the [[Press]]&lt;br /&gt;
* Read and post on the [[:Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]&lt;br /&gt;
* Chat on one of the [[:Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels&lt;br /&gt;
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works&lt;br /&gt;
* Ask questions on the [http://bitcoin.stackexchange.com Bitcoin Stack Exchange]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=77</id>
		<title>Intrebari Frecvente</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=77"/>
		<updated>2013-05-24T07:48:19Z</updated>

		<summary type="html">&lt;p&gt;8fold: /* General */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;).&lt;br /&gt;
Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Adresă Bitcoin]]. &lt;br /&gt;
Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
There are a variety of ways to acquire bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Accept bitcoins as payment for goods or services.&lt;br /&gt;
* The most common way to buy bitcoins are the [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* There are several services where you can [[Buying_Bitcoins_(the_noob_version)|trade them]] for traditional currency.&lt;br /&gt;
* Find someone to trade cash for bitcoins in-person through a [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participate in a [[Pooled mining|mining pool]].&lt;br /&gt;
* If you have a lot of mining hardware, you can solo mine and attempt to create a new [[block]] (currently yields 25 bitcoins plus transaction fees).&lt;br /&gt;
* Visit sites that provide [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
===Garantează Bitcoin un flux gratis de bani?===&lt;br /&gt;
&lt;br /&gt;
Since Bitcoin is a new technology, what it is and how it works may be initially unclear.  Bitcoin is sometimes presented as being one of three things:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;Some sort of online &#039;get-rich-quick&#039; scam.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A loophole in the market economy, the installation of which guarantees a steady influx of cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A sure investment that will almost certainly yield a profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
In fact, none of the above are true.  Let&#039;s look at them independently.&lt;br /&gt;
&lt;br /&gt;
;Is Bitcoin a &#039;get-rich-quick&#039; scheme?&lt;br /&gt;
:If you&#039;ve spent much time on the Internet, you&#039;ve probably seen ads for many &#039;get-rich-quick&#039; schemes. These ads usually promise huge profits for a small amounts of easy work.  Such schemes are usually pyramid/matrix-style schemes that make money from their own employees and offer nothing of any real value.  Most convince one to buy packages that will make them earn hundreds a day, which in fact  have the buyer distribute more such ads, and make minute profits.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin is in no way similar to these schemes. Bitcoin doesn&#039;t promise windfall profits. There is no way for the developers to make money from your involvement or to take money from you. That bitcoins are nearly impossible to acquire without the owner&#039;s consent represents one of its greatest strengths.  Bitcoin is an experimental, virtual currency that may succeed or may fail. None of its developers expect to get rich off of it. &lt;br /&gt;
&lt;br /&gt;
:A more detailed answer to this question can be found [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
;Will I make money by installing the client?&lt;br /&gt;
:Most people who use Bitcoin don&#039;t earn anything by doing so, and the default client has no built-in way to earn Bitcoins.  A small minority of people with dedicated, high-performance hardware do earn some Bitcoins by &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generating new bitcoins, see [[#What is mining?|What is mining?]]) with special software, but joining Bitcoin shouldn&#039;t be construed as being the road to riches.  Most Bitcoin users get involved because they find the project conceptually interesting and don&#039;t earn anything by doing so.  This is also why you won&#039;t find much speculation about the political or economic repercussions of Bitcoin anywhere on this site: Bitcoin developers owe their dedication to the project&#039;s intellectual yieldings more than to those of a monetary nature.  Bitcoin is still taking its first baby steps; it may go on to do great things but right now it only has something to offer those chasing conceptually interesting projects or bleeding edge technology.&lt;br /&gt;
&lt;br /&gt;
;As an investment, is Bitcoin a sure thing?&lt;br /&gt;
:Bitcoin is a new and interesting electronic currency, the value of which is not backed by any single government or organization.  Like other currencies, it is worth something partly because people are willing to trade it for goods and services. Its exchange rate fluctuates continuously, and sometimes wildly. It lacks wide acceptance and is vulnerable to manipulation by parties with modest funding. Security incidents such as website and account compromise may trigger major sell-offs. Other fluctuations can build into positive feedback loops and cause much larger exchange rate fluctuations. Anyone who puts money into Bitcoin should understand the risk they are taking and consider it a high-risk currency. Later, as Bitcoin becomes better known and more widely accepted, it may stabilize, but for the time being it is unpredictable. Any investment in Bitcoin should be done carefully and with a clear plan to manage the risk.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpara bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
It is possible to buy [[physical bitcoins]] with PayPal but it is otherwise difficult and/or expensive to do so for non-physical bitcoins, because of significant risk to the seller. &lt;br /&gt;
&lt;br /&gt;
While it is possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most exchanges do not allow funding through PayPal. This is due to repeated cases where someone pays for bitcoins with Paypal, receives their bitcoins, and then fraudulently complains to Paypal that they never received their purchase. PayPal often sides with the fraudulent buyer in this case, which means any seller needs to cover that risk with higher fees or refuse to accept PayPal altogether.&lt;br /&gt;
&lt;br /&gt;
Buying Bitcoins from individuals this way is still possible, but requires the seller to have some trust that the buyer will not file a claim with PayPal to reverse the payment.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot gasi un forum dedicat discutiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Please visit the  [[Bitcoin:Community_portal#Bitcoin_Community_Forums_on_various_platforms|Community Portal]] for links to Bitcoin-related forums.&lt;br /&gt;
&lt;br /&gt;
=== Cum sunt bitcoinii creati? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]&lt;br /&gt;
New bitcoins are generated by the network through the process of &amp;quot;[[#What is mining?|&#039;&#039;mining&#039;&#039;]]&amp;quot;. In a process that is similar to a continuous raffle draw, mining nodes on the network are awarded bitcoins each time they find the solution to a certain mathematical problem (and thereby create a new [[block]]). Creating a block is a [[proof of work]] with a difficulty that varies with the overall strength of the network.  The reward for solving a block is [[Controlled Currency Supply|automatically adjusted]] so that roughly every four years of operation of the Bitcoin network, half the amount of bitcoins created in the prior 4 years are created. {{formatnum:10500000}} bitcoins were created in the first 4 (approx.) years from January 2009 to November 2012.  Every four years thereafter this amount halves, so it will be {{formatnum:5250000}} over years 4-8, {{formatnum:2625000}} over years 8-12, and so on. Thus the total number of bitcoins in existence will never exceed {{formatnum:21000000}}. See [[Controlled Currency Supply]].&lt;br /&gt;
&lt;br /&gt;
Blocks are [[Mining|mined]] every 10 minutes, on average and for the first four years ({{formatnum:210000}} blocks) each block included 50 new bitcoins.  As the amount of processing power directed at mining changes, the difficulty of creating new bitcoins changes.  This difficulty factor is calculated every 2016 blocks and is based upon the time taken to generate the previous 2016 blocks. See [[Mining]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numarul total de bitcoini?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Current count]. Also see [https://blockchain.info/charts/total-bitcoins Total bitcoins in circulation chart]&lt;br /&gt;
&lt;br /&gt;
The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first {{formatnum:210000}} blocks, 25 BTC for the next {{formatnum:210000}} blocks, then 12.5 BTC, 6.25 BTC and so on.&lt;br /&gt;
&lt;br /&gt;
=== Cat de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
A bitcoin can be divided down to 8 decimal places. Therefore, 0.00000001 BTC is the smallest amount that can be handled in a transaction. If necessary, the protocol and related software can be modified to handle even smaller amounts.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominarile bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)&lt;br /&gt;
* 0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)&lt;br /&gt;
* 0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)&lt;br /&gt;
&lt;br /&gt;
The above follows the accepted international SI prefixes for hundredths, thousandths, and millionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won&#039;t be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as &amp;quot;cent&amp;quot;, &amp;quot;nickel&amp;quot;, &amp;quot;dime&amp;quot;, &amp;quot;pence&amp;quot;, &amp;quot;pound&amp;quot;, &amp;quot;kopek&amp;quot; and so on are to be discouraged; this is a worldwide currency.&lt;br /&gt;
&lt;br /&gt;
One exception is the &amp;quot;satoshi&amp;quot; which is smallest denomination currently possible &lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)&lt;br /&gt;
which is so named in honour of Satoshi Nakamoto, the pseudonym of the inventor of Bitcoin.&lt;br /&gt;
&lt;br /&gt;
For an overview of all defined units of Bitcoin (including less common and niche units), see [[Units]].&lt;br /&gt;
&lt;br /&gt;
Further discussion on this topic can be found on the forums here:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum functioneaza injumatatirea cand numarul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Eventually the reward will go from 0.00000001 BTC to zero and no more bitcoins will be created.  &lt;br /&gt;
&lt;br /&gt;
The block reward calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by two and rounded down. The integer is equal to the value in BTC * 100,000,000 since internally in the reference client software, all Bitcoin balances and values are stored as unsigned integers.&lt;br /&gt;
&lt;br /&gt;
With an initial block reward of 50 BTC, it will take many 4-year periods for the block reward to reach zero.&lt;br /&gt;
&lt;br /&gt;
=== Cat timp va dura pana vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
The last block that will generate coins will be block #6,929,999 which should be generated at or near the year 2140. The total number of coins in circulation will then remain static at 20,999,999.9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Even if the allowed precision is expanded from the current 8 decimals, the total BTC in circulation will always be slightly below 21 million (assuming everything else stays the same). For example, with 16 decimals of precision, the end total would be 20,999,999.999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Daca nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Absolutely!  Even before the creation of coins ends, the use of [[transaction fee|transaction fees]] will likely make creating new blocks more valuable from the fees than the new coins being created.  When coin generation ends, these fees will sustain the ability to use bitcoins and the Bitcoin network. There is no practical limit on the number of blocks that will be mined in the future.&lt;br /&gt;
&lt;br /&gt;
=== Dar daca nu mai sunt generate monezi, ce se intampla cand se pierd bitcoini? Nu ar fi o problema? ===&lt;br /&gt;
&lt;br /&gt;
Because of the law of supply and demand, when fewer bitcoins are available the ones that are left will be in higher demand, and therefore will have a higher value. So, as Bitcoins are lost, the remaining bitcoins will eventually increase in value to compensate. As the value of a bitcoin increases, the number of bitcoins required to purchase an item &#039;&#039;&#039;de&#039;&#039;&#039;creases. This is a [[Deflationary spiral|deflationary economic model]]. As the average transaction size reduces, transactions will probably be denominated in sub-units of a bitcoin such as millibitcoins (&amp;quot;Millies&amp;quot;) or microbitcoins (&amp;quot;Mikes&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
The Bitcoin protocol uses a base unit of one hundred-millionth of a Bitcoin (&amp;quot;a Satoshi&amp;quot;), but unused bits are available in the protocol fields that could be used to denote even smaller subdivisions.&lt;br /&gt;
&lt;br /&gt;
=== Daca fiecare tranzactie este emisa prin retea, atunci Bitcoin este scalabil? ===&lt;br /&gt;
The Bitcoin protocol allows lightweight clients that can use Bitcoin without downloading the entire transaction history. As traffic grows and this becomes more critical, implementations of the concept will be developed. Full network nodes will at some point become a more specialized service.&lt;br /&gt;
&lt;br /&gt;
With some modifications to the software, full Bitcoin nodes could easily keep up with both VISA and MasterCard combined, using only fairly modest hardware (a single high end server by todays standards). It is worth noting that the MasterCard network is structured somewhat like Bitcoin itself - as a peer to peer broadcast network.&lt;br /&gt;
&lt;br /&gt;
Learn more about [[Scalability]].&lt;br /&gt;
&lt;br /&gt;
==Economie==&lt;br /&gt;
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===&lt;br /&gt;
Bitcoins have value because they are useful and because they are [[Controlled Currency Supply|scarce]]. As they are accepted by more merchants, their value will [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabilize]. See the [[Trade|list of Bitcoin-accepting sites]].&lt;br /&gt;
&lt;br /&gt;
When we say that a currency is backed up by gold, we mean that there&#039;s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.&lt;br /&gt;
&lt;br /&gt;
It&#039;s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn&#039;t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn&#039;t make anything valuable. For example, your fingerprints are scarce, but that doesn&#039;t mean they have any exchange value.&lt;br /&gt;
&lt;br /&gt;
Alternatively it needs to be added that while the law of supply and demand applies it does not guarantee value of Bitcoins in the future.  If confidence in Bitcoins is lost then it will not matter that the supply can no longer be increased, the demand will fall off with all holders trying to get rid of their coins.  An example of this can be seen in cases of state currencies, in cases when the state in question dissolves and so no new supply of the currency is available (the central authority managing the supply is gone), however the demand for the currency falls sharply because confidence in its purchasing power disappears.  Of-course Bitcoins do not have such central authority managing the supply of the coins, but it does not prevent confidence from eroding due to other situations that are not necessarily predictable.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
Yes, in the same way as the euro and dollar are. They only have value in exchange and have no inherent value. If everyone suddenly stopped accepting your dollars, euros or bitcoins, the &amp;quot;bubble&amp;quot; would burst and their value would drop to zero. But that is unlikely to happen: even in Somalia, where the government collapsed 20 years ago, [http://en.wikipedia.org/wiki/Somali_shilling Somali shillings] are still accepted as payment.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schema piramidala/Ponzi? ===&lt;br /&gt;
In a Ponzi Scheme, the founders persuade investors that they’ll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.&lt;br /&gt;
&lt;br /&gt;
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.&lt;br /&gt;
&lt;br /&gt;
The fact that early adopters benefit more doesn&#039;t alone make anything a Ponzi scheme. All good investments in successful companies have this quality.&lt;br /&gt;
&lt;br /&gt;
=== Nu cumva Bitcoin favorizeaza pe nedrept investitorii initiali? ===&lt;br /&gt;
Early adopters have a large number of bitcoins now because they took a risk and invested resources in an unproven technology. By so doing, they have helped Bitcoin become what it is now and what it will be in the future (hopefully, a ubiquitous decentralized digital currency). It is only fair they will reap the benefits of their successful investment.&lt;br /&gt;
&lt;br /&gt;
In any case, any bitcoin generated will probably change hands dozens of time as a medium of exchange, so the profit made from the initial distribution will be insignificant compared to the total commerce enabled by Bitcoin.&lt;br /&gt;
&lt;br /&gt;
Since the pricing of Bitcoins has fallen greatly from its June 2011 peak, prices today are much more similar to those enjoyed by many early adopters.  Those who are buying Bitcoins today likely believe that Bitcoin will grow significantly in the future.  Setting aside the brief opportunity to have sold Bitcoins at the June 2011 peak enjoyed by few, the early-adopter window is arguably still open.&lt;br /&gt;
&lt;br /&gt;
===Pierderea de portofele si faptul ca numarul de bitcoini este finit nu ar cauza deflatie excesiva, distrugand Bitcoinul? ===&lt;br /&gt;
Worries about Bitcoin being destroyed by deflation are not entirely unfounded.  Unlike most currencies, which experience inflation as their founding institutions create more and more units, Bitcoin will likely experience gradual deflation with the passage of time.  Bitcoin is unique in that only a small amount of units will ever be produced (twenty-one million to be exact), this number has been known since the project&#039;s inception, and the units are created at a predictable rate.&lt;br /&gt;
&lt;br /&gt;
Also, Bitcoin users are faced with a danger that doesn&#039;t threaten users of any other currency: if a Bitcoin user loses his wallet, his money is gone forever, unless he finds it again. And not just to him; it&#039;s gone completely out of circulation, rendered utterly inaccessible to anyone. As people will lose their wallets, the total number of Bitcoins will slowly decrease.&lt;br /&gt;
&lt;br /&gt;
Therefore, Bitcoin seems to be faced with a unique problem. Whereas most currencies inflate over time, Bitcoin will mostly likely do just the opposite. Time will see the irretrievable loss of an ever-increasing number of Bitcoins. An already small number will be permanently whittled down further and further. And as there become fewer and fewer Bitcoins, the laws of supply and demand suggest that their value will probably continually rise.&lt;br /&gt;
&lt;br /&gt;
Thus Bitcoin is bound to once again stray into mysterious territory, because no one exactly knows what happens to a currency that grows continually more valuable. Many economists claim that a low level of inflation is a good thing for a currency, but nobody is quite sure about what might happens to one that continually deflates. Although deflation could hardly be called a rare phenomenon, steady, constant deflation is unheard of.  There may be a lot of speculation, no one has any hard data to back up their claims.&lt;br /&gt;
&lt;br /&gt;
That being said, there is a mechanism in place to combat the obvious consequences.  Extreme deflation would render most currencies highly impractical: if a single Canadian dollar could suddenly buy the holder a car, how would one go about buying bread or candy?  Even pennies would fetch more than a person could carry. Bitcoin, however, offers a simple and stylish solution: infinite divisibility.  Bitcoins can be divided up and trade into as small of pieces as one wants, so no matter how valuable Bitcoins become, one can trade them in practical quantities.  &lt;br /&gt;
&lt;br /&gt;
In fact, infinite divisibility should allow Bitcoins to function in cases of extreme wallet loss.  Even if, in the far future, so many people have lost their wallets that only a single Bitcoin, or a fraction of one, remains, Bitcoin should continue to function just fine. No one can claim to be sure what is going to happen, but deflation may prove to present a smaller threat than many expect.&lt;br /&gt;
&lt;br /&gt;
For more information, see the [[Deflationary spiral]] page.&lt;br /&gt;
&lt;br /&gt;
=== Daca cineva ar cumpara fiecare bitcoin care a fost creat? ===&lt;br /&gt;
Bitcoin markets are competitive -- meaning the price of a bitcoin will rise or fall depending on supply and demand at certain price levels.  Only a fraction of bitcoins issued to date are found on the exchange markets for sale.  So even though technically a buyer with lots of money could buy all the bitcoins offered for sale, unless those holding the rest of the bitcoins offer them for sale as well, even the wealthiest, most determined buyer can&#039;t get at them.&lt;br /&gt;
&lt;br /&gt;
Additionally, new currency continues to be issued daily and will continue to do so for decades though over time the rate at which they are issued declines to insignificant levels.  Those who are mining aren&#039;t obligated to sell their bitcoins so not all bitcoins will make it to the markets even.&lt;br /&gt;
&lt;br /&gt;
This situation doesn&#039;t suggest, however, that the markets aren&#039;t vulnerable to price manipulation.  It doesn&#039;t take significant amounts of money to move the market price up or down and thus Bitcoin remains a volatile asset.&lt;br /&gt;
&lt;br /&gt;
===Daca cineva creaza un nou lant de blocuri(block chain), sau o noua moneda digitala care scoate Bitcoinul din uz?===&lt;br /&gt;
&lt;br /&gt;
That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
&lt;br /&gt;
As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
&lt;br /&gt;
A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
&lt;br /&gt;
Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
&lt;br /&gt;
A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
&lt;br /&gt;
A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
&lt;br /&gt;
This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoinul susceptibil manipularii valorii sale? ===&lt;br /&gt;
&lt;br /&gt;
The current low market cap of Bitcoin means that any investor with deep enough pockets can significantly change/manipulate the rate. Is this a problem?&lt;br /&gt;
&lt;br /&gt;
This is only a problem if you are investing in Bitcoin for short period of time. A manipulator can&#039;t change the fundamentals, and over a period of 5-10 years they will win over any short term manipulations.&lt;br /&gt;
&lt;br /&gt;
==Efectuarea si primirea de plati==&lt;br /&gt;
&lt;br /&gt;
=== De ce trebuie sa astept 10 minute inainte sa pot cheltui banii primiti? ===&lt;br /&gt;
&lt;br /&gt;
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. &lt;br /&gt;
&lt;br /&gt;
You can see how long all other recent transactions have taken here: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
&lt;br /&gt;
[[Blocks]] (shown as &amp;quot;confirmations&amp;quot; in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it&#039;s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!&lt;br /&gt;
&lt;br /&gt;
Ten minutes was specifically chosen by [[Satoshi]] as a tradeoff between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. For a more technical explanation, see Satoshi&#039;s [http://www.bitcoin.org/bitcoin.pdf original technical paper].&lt;br /&gt;
&lt;br /&gt;
[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
&lt;br /&gt;
=== Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
YES, you do, IF the transaction is non-recourse. The Bitcoin reference software does not display transactions as confirmed until six blocks have passed (confirmations). As transactions are burred in the chain they become increasingly non-reversible but are very reversible before the first confirmation. Two to six confirmations are recommended for non-recourse situations depending on the value of the transactions involved.&lt;br /&gt;
&lt;br /&gt;
When people ask this question they are usually thinking about applications like supermarkets.  This generally is a recourse situation: if somebody tries to double-spend on a face-to-face transaction it might work a few times, but probabalistically speaking eventually one of the double-spends will get noticed, and the penalty for shoplifting charges in most localities is calibrated to be several times worse than the proceeds of a single shoplifting event.&lt;br /&gt;
&lt;br /&gt;
Double-spends might be a concern for something like a snack machine in a low-traffic area with no nearby security cameras.  Such a machine shouldn&#039;t honor 0-confirmation payments, and should instead use some other mechanism of clearing Bitcoin or validating transactions against reversal, see the wiki article [[Myths#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|here]] for alternatives.&lt;br /&gt;
&lt;br /&gt;
Applications that require immediate payment processing, like supermarkets or snack machines, need to manage the risks. Here is one way to reverse an unconfirmed payment:&lt;br /&gt;
&lt;br /&gt;
A [[Double-spending#Finney_attack|Finney attack]], in which an attacker mines a block containing a movement of some coins back to themselves. Once they find a block solution, they quickly go to a merchant and make a purchase, then broadcast the block, thus taking back the coins. This attack is a risk primarily for goods that are dispatched immediately, like song downloads or currency trades. Because the attacker can&#039;t choose the time of the attack, it isn&#039;t a risk for merchants such as supermarkets where you can&#039;t choose exactly when to pay (due to queues, etc). The attack can fail if somebody else finds a block containing the purchasing transaction before you release your own block, therefore, merchants can reduce but not eliminate the risk by making purchasers wait some length of time that&#039;s less than a confirm.&lt;br /&gt;
&lt;br /&gt;
Because pulling off this attack is not trivial, merchants who need to sell things automatically and instantly are most likely to just price the cost of reversal fraud in, or use insurance.&lt;br /&gt;
&lt;br /&gt;
=== I was sent some bitcoins and they haven&#039;t arrived yet! Where are they? ===&lt;br /&gt;
&lt;br /&gt;
Don&#039;t panic!  There are a number of reasons why your bitcoins might not show up yet, and a number of ways to diagnose them.  &lt;br /&gt;
&lt;br /&gt;
The latest version of the Bitcoin-Qt client tells you how far it has yet to go in downloading the blockchain.  Hover over the icon in the bottom right corner of the client to learn your client&#039;s status.&lt;br /&gt;
&lt;br /&gt;
If it has not caught up then it&#039;s possible that your transaction hasn&#039;t been included in a block yet.  &lt;br /&gt;
&lt;br /&gt;
You can check pending transactions in the network by going [http://blockchain.info here] and then searching for your address.  If the transaction is listed here then it&#039;s a matter of waiting until it gets included in a block before it will show in your client.  &lt;br /&gt;
&lt;br /&gt;
If the transaction is based on a coin that was in a recent transaction then it could be considered a low priority transaction. Transfers can take longer if the transaction fee paid was not high enough.  If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.&lt;br /&gt;
&lt;br /&gt;
=== Why does my Bitcoin address keep changing? ===&lt;br /&gt;
&lt;br /&gt;
Whenever the address listed in &amp;quot;Your address&amp;quot; receives a transaction, Bitcoin replaces it with a new address. This is meant to encourage you to use a new address for every transaction, which enhances [[anonymity]]. All of your old addresses are still usable: you can see them in &#039;&#039;Settings -&amp;gt; Your Receiving Addresses&#039;&#039;.&lt;br /&gt;
&lt;br /&gt;
===How much will the transaction fee be?===&lt;br /&gt;
&lt;br /&gt;
Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
&lt;br /&gt;
The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
&lt;br /&gt;
A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
&lt;br /&gt;
Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
&lt;br /&gt;
As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
&lt;br /&gt;
=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
&lt;br /&gt;
If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
&lt;br /&gt;
=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
&lt;br /&gt;
The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
&lt;br /&gt;
In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
&lt;br /&gt;
When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
&lt;br /&gt;
If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
&lt;br /&gt;
==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
&lt;br /&gt;
If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
&lt;br /&gt;
=== How does the peer finding mechanism work? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
&lt;br /&gt;
==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
&lt;br /&gt;
Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
&lt;br /&gt;
===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
&lt;br /&gt;
===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Help==&lt;br /&gt;
===I&#039;d like to learn more.  Where can I get help?===&lt;br /&gt;
&lt;br /&gt;
* Read the [[Introduction|introduction to bitcoin]] &lt;br /&gt;
* See the videos, podcasts, and blog posts from the [[Press]]&lt;br /&gt;
* Read and post on the [[:Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]&lt;br /&gt;
* Chat on one of the [[:Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels&lt;br /&gt;
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works&lt;br /&gt;
* Ask questions on the [http://bitcoin.stackexchange.com Bitcoin Stack Exchange]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=76</id>
		<title>Intrebari Frecvente</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=76"/>
		<updated>2013-05-24T07:42:55Z</updated>

		<summary type="html">&lt;p&gt;8fold: /* Ce sunt bitcoinii? */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;).&lt;br /&gt;
Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Adresă Bitcoin]]. &lt;br /&gt;
Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
There are a variety of ways to acquire bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Accept bitcoins as payment for goods or services.&lt;br /&gt;
* The most common way to buy bitcoins are the [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* There are several services where you can [[Buying_Bitcoins_(the_noob_version)|trade them]] for traditional currency.&lt;br /&gt;
* Find someone to trade cash for bitcoins in-person through a [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participate in a [[Pooled mining|mining pool]].&lt;br /&gt;
* If you have a lot of mining hardware, you can solo mine and attempt to create a new [[block]] (currently yields 25 bitcoins plus transaction fees).&lt;br /&gt;
* Visit sites that provide [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
===Bitcoin garanteaza un flux gratis de bani?===&lt;br /&gt;
&lt;br /&gt;
Since Bitcoin is a new technology, what it is and how it works may be initially unclear.  Bitcoin is sometimes presented as being one of three things:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;Some sort of online &#039;get-rich-quick&#039; scam.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A loophole in the market economy, the installation of which guarantees a steady influx of cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A sure investment that will almost certainly yield a profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
In fact, none of the above are true.  Let&#039;s look at them independently.&lt;br /&gt;
&lt;br /&gt;
;Is Bitcoin a &#039;get-rich-quick&#039; scheme?&lt;br /&gt;
:If you&#039;ve spent much time on the Internet, you&#039;ve probably seen ads for many &#039;get-rich-quick&#039; schemes. These ads usually promise huge profits for a small amounts of easy work.  Such schemes are usually pyramid/matrix-style schemes that make money from their own employees and offer nothing of any real value.  Most convince one to buy packages that will make them earn hundreds a day, which in fact  have the buyer distribute more such ads, and make minute profits.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin is in no way similar to these schemes. Bitcoin doesn&#039;t promise windfall profits. There is no way for the developers to make money from your involvement or to take money from you. That bitcoins are nearly impossible to acquire without the owner&#039;s consent represents one of its greatest strengths.  Bitcoin is an experimental, virtual currency that may succeed or may fail. None of its developers expect to get rich off of it. &lt;br /&gt;
&lt;br /&gt;
:A more detailed answer to this question can be found [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
;Will I make money by installing the client?&lt;br /&gt;
:Most people who use Bitcoin don&#039;t earn anything by doing so, and the default client has no built-in way to earn Bitcoins.  A small minority of people with dedicated, high-performance hardware do earn some Bitcoins by &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generating new bitcoins, see [[#What is mining?|What is mining?]]) with special software, but joining Bitcoin shouldn&#039;t be construed as being the road to riches.  Most Bitcoin users get involved because they find the project conceptually interesting and don&#039;t earn anything by doing so.  This is also why you won&#039;t find much speculation about the political or economic repercussions of Bitcoin anywhere on this site: Bitcoin developers owe their dedication to the project&#039;s intellectual yieldings more than to those of a monetary nature.  Bitcoin is still taking its first baby steps; it may go on to do great things but right now it only has something to offer those chasing conceptually interesting projects or bleeding edge technology.&lt;br /&gt;
&lt;br /&gt;
;As an investment, is Bitcoin a sure thing?&lt;br /&gt;
:Bitcoin is a new and interesting electronic currency, the value of which is not backed by any single government or organization.  Like other currencies, it is worth something partly because people are willing to trade it for goods and services. Its exchange rate fluctuates continuously, and sometimes wildly. It lacks wide acceptance and is vulnerable to manipulation by parties with modest funding. Security incidents such as website and account compromise may trigger major sell-offs. Other fluctuations can build into positive feedback loops and cause much larger exchange rate fluctuations. Anyone who puts money into Bitcoin should understand the risk they are taking and consider it a high-risk currency. Later, as Bitcoin becomes better known and more widely accepted, it may stabilize, but for the time being it is unpredictable. Any investment in Bitcoin should be done carefully and with a clear plan to manage the risk.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpara bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
It is possible to buy [[physical bitcoins]] with PayPal but it is otherwise difficult and/or expensive to do so for non-physical bitcoins, because of significant risk to the seller. &lt;br /&gt;
&lt;br /&gt;
While it is possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most exchanges do not allow funding through PayPal. This is due to repeated cases where someone pays for bitcoins with Paypal, receives their bitcoins, and then fraudulently complains to Paypal that they never received their purchase. PayPal often sides with the fraudulent buyer in this case, which means any seller needs to cover that risk with higher fees or refuse to accept PayPal altogether.&lt;br /&gt;
&lt;br /&gt;
Buying Bitcoins from individuals this way is still possible, but requires the seller to have some trust that the buyer will not file a claim with PayPal to reverse the payment.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot gasi un forum dedicat discutiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Please visit the  [[Bitcoin:Community_portal#Bitcoin_Community_Forums_on_various_platforms|Community Portal]] for links to Bitcoin-related forums.&lt;br /&gt;
&lt;br /&gt;
=== Cum sunt bitcoinii creati? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]&lt;br /&gt;
New bitcoins are generated by the network through the process of &amp;quot;[[#What is mining?|&#039;&#039;mining&#039;&#039;]]&amp;quot;. In a process that is similar to a continuous raffle draw, mining nodes on the network are awarded bitcoins each time they find the solution to a certain mathematical problem (and thereby create a new [[block]]). Creating a block is a [[proof of work]] with a difficulty that varies with the overall strength of the network.  The reward for solving a block is [[Controlled Currency Supply|automatically adjusted]] so that roughly every four years of operation of the Bitcoin network, half the amount of bitcoins created in the prior 4 years are created. {{formatnum:10500000}} bitcoins were created in the first 4 (approx.) years from January 2009 to November 2012.  Every four years thereafter this amount halves, so it will be {{formatnum:5250000}} over years 4-8, {{formatnum:2625000}} over years 8-12, and so on. Thus the total number of bitcoins in existence will never exceed {{formatnum:21000000}}. See [[Controlled Currency Supply]].&lt;br /&gt;
&lt;br /&gt;
Blocks are [[Mining|mined]] every 10 minutes, on average and for the first four years ({{formatnum:210000}} blocks) each block included 50 new bitcoins.  As the amount of processing power directed at mining changes, the difficulty of creating new bitcoins changes.  This difficulty factor is calculated every 2016 blocks and is based upon the time taken to generate the previous 2016 blocks. See [[Mining]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numarul total de bitcoini?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Current count]. Also see [https://blockchain.info/charts/total-bitcoins Total bitcoins in circulation chart]&lt;br /&gt;
&lt;br /&gt;
The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first {{formatnum:210000}} blocks, 25 BTC for the next {{formatnum:210000}} blocks, then 12.5 BTC, 6.25 BTC and so on.&lt;br /&gt;
&lt;br /&gt;
=== Cat de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
A bitcoin can be divided down to 8 decimal places. Therefore, 0.00000001 BTC is the smallest amount that can be handled in a transaction. If necessary, the protocol and related software can be modified to handle even smaller amounts.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominarile bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)&lt;br /&gt;
* 0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)&lt;br /&gt;
* 0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)&lt;br /&gt;
&lt;br /&gt;
The above follows the accepted international SI prefixes for hundredths, thousandths, and millionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won&#039;t be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as &amp;quot;cent&amp;quot;, &amp;quot;nickel&amp;quot;, &amp;quot;dime&amp;quot;, &amp;quot;pence&amp;quot;, &amp;quot;pound&amp;quot;, &amp;quot;kopek&amp;quot; and so on are to be discouraged; this is a worldwide currency.&lt;br /&gt;
&lt;br /&gt;
One exception is the &amp;quot;satoshi&amp;quot; which is smallest denomination currently possible &lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)&lt;br /&gt;
which is so named in honour of Satoshi Nakamoto, the pseudonym of the inventor of Bitcoin.&lt;br /&gt;
&lt;br /&gt;
For an overview of all defined units of Bitcoin (including less common and niche units), see [[Units]].&lt;br /&gt;
&lt;br /&gt;
Further discussion on this topic can be found on the forums here:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum functioneaza injumatatirea cand numarul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Eventually the reward will go from 0.00000001 BTC to zero and no more bitcoins will be created.  &lt;br /&gt;
&lt;br /&gt;
The block reward calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by two and rounded down. The integer is equal to the value in BTC * 100,000,000 since internally in the reference client software, all Bitcoin balances and values are stored as unsigned integers.&lt;br /&gt;
&lt;br /&gt;
With an initial block reward of 50 BTC, it will take many 4-year periods for the block reward to reach zero.&lt;br /&gt;
&lt;br /&gt;
=== Cat timp va dura pana vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
The last block that will generate coins will be block #6,929,999 which should be generated at or near the year 2140. The total number of coins in circulation will then remain static at 20,999,999.9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Even if the allowed precision is expanded from the current 8 decimals, the total BTC in circulation will always be slightly below 21 million (assuming everything else stays the same). For example, with 16 decimals of precision, the end total would be 20,999,999.999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Daca nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Absolutely!  Even before the creation of coins ends, the use of [[transaction fee|transaction fees]] will likely make creating new blocks more valuable from the fees than the new coins being created.  When coin generation ends, these fees will sustain the ability to use bitcoins and the Bitcoin network. There is no practical limit on the number of blocks that will be mined in the future.&lt;br /&gt;
&lt;br /&gt;
=== Dar daca nu mai sunt generate monezi, ce se intampla cand se pierd bitcoini? Nu ar fi o problema? ===&lt;br /&gt;
&lt;br /&gt;
Because of the law of supply and demand, when fewer bitcoins are available the ones that are left will be in higher demand, and therefore will have a higher value. So, as Bitcoins are lost, the remaining bitcoins will eventually increase in value to compensate. As the value of a bitcoin increases, the number of bitcoins required to purchase an item &#039;&#039;&#039;de&#039;&#039;&#039;creases. This is a [[Deflationary spiral|deflationary economic model]]. As the average transaction size reduces, transactions will probably be denominated in sub-units of a bitcoin such as millibitcoins (&amp;quot;Millies&amp;quot;) or microbitcoins (&amp;quot;Mikes&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
The Bitcoin protocol uses a base unit of one hundred-millionth of a Bitcoin (&amp;quot;a Satoshi&amp;quot;), but unused bits are available in the protocol fields that could be used to denote even smaller subdivisions.&lt;br /&gt;
&lt;br /&gt;
=== Daca fiecare tranzactie este emisa prin retea, atunci Bitcoin este scalabil? ===&lt;br /&gt;
The Bitcoin protocol allows lightweight clients that can use Bitcoin without downloading the entire transaction history. As traffic grows and this becomes more critical, implementations of the concept will be developed. Full network nodes will at some point become a more specialized service.&lt;br /&gt;
&lt;br /&gt;
With some modifications to the software, full Bitcoin nodes could easily keep up with both VISA and MasterCard combined, using only fairly modest hardware (a single high end server by todays standards). It is worth noting that the MasterCard network is structured somewhat like Bitcoin itself - as a peer to peer broadcast network.&lt;br /&gt;
&lt;br /&gt;
Learn more about [[Scalability]].&lt;br /&gt;
&lt;br /&gt;
==Economie==&lt;br /&gt;
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===&lt;br /&gt;
Bitcoins have value because they are useful and because they are [[Controlled Currency Supply|scarce]]. As they are accepted by more merchants, their value will [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabilize]. See the [[Trade|list of Bitcoin-accepting sites]].&lt;br /&gt;
&lt;br /&gt;
When we say that a currency is backed up by gold, we mean that there&#039;s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.&lt;br /&gt;
&lt;br /&gt;
It&#039;s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn&#039;t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn&#039;t make anything valuable. For example, your fingerprints are scarce, but that doesn&#039;t mean they have any exchange value.&lt;br /&gt;
&lt;br /&gt;
Alternatively it needs to be added that while the law of supply and demand applies it does not guarantee value of Bitcoins in the future.  If confidence in Bitcoins is lost then it will not matter that the supply can no longer be increased, the demand will fall off with all holders trying to get rid of their coins.  An example of this can be seen in cases of state currencies, in cases when the state in question dissolves and so no new supply of the currency is available (the central authority managing the supply is gone), however the demand for the currency falls sharply because confidence in its purchasing power disappears.  Of-course Bitcoins do not have such central authority managing the supply of the coins, but it does not prevent confidence from eroding due to other situations that are not necessarily predictable.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
Yes, in the same way as the euro and dollar are. They only have value in exchange and have no inherent value. If everyone suddenly stopped accepting your dollars, euros or bitcoins, the &amp;quot;bubble&amp;quot; would burst and their value would drop to zero. But that is unlikely to happen: even in Somalia, where the government collapsed 20 years ago, [http://en.wikipedia.org/wiki/Somali_shilling Somali shillings] are still accepted as payment.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schema piramidala/Ponzi? ===&lt;br /&gt;
In a Ponzi Scheme, the founders persuade investors that they’ll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.&lt;br /&gt;
&lt;br /&gt;
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.&lt;br /&gt;
&lt;br /&gt;
The fact that early adopters benefit more doesn&#039;t alone make anything a Ponzi scheme. All good investments in successful companies have this quality.&lt;br /&gt;
&lt;br /&gt;
=== Nu cumva Bitcoin favorizeaza pe nedrept investitorii initiali? ===&lt;br /&gt;
Early adopters have a large number of bitcoins now because they took a risk and invested resources in an unproven technology. By so doing, they have helped Bitcoin become what it is now and what it will be in the future (hopefully, a ubiquitous decentralized digital currency). It is only fair they will reap the benefits of their successful investment.&lt;br /&gt;
&lt;br /&gt;
In any case, any bitcoin generated will probably change hands dozens of time as a medium of exchange, so the profit made from the initial distribution will be insignificant compared to the total commerce enabled by Bitcoin.&lt;br /&gt;
&lt;br /&gt;
Since the pricing of Bitcoins has fallen greatly from its June 2011 peak, prices today are much more similar to those enjoyed by many early adopters.  Those who are buying Bitcoins today likely believe that Bitcoin will grow significantly in the future.  Setting aside the brief opportunity to have sold Bitcoins at the June 2011 peak enjoyed by few, the early-adopter window is arguably still open.&lt;br /&gt;
&lt;br /&gt;
===Pierderea de portofele si faptul ca numarul de bitcoini este finit nu ar cauza deflatie excesiva, distrugand Bitcoinul? ===&lt;br /&gt;
Worries about Bitcoin being destroyed by deflation are not entirely unfounded.  Unlike most currencies, which experience inflation as their founding institutions create more and more units, Bitcoin will likely experience gradual deflation with the passage of time.  Bitcoin is unique in that only a small amount of units will ever be produced (twenty-one million to be exact), this number has been known since the project&#039;s inception, and the units are created at a predictable rate.&lt;br /&gt;
&lt;br /&gt;
Also, Bitcoin users are faced with a danger that doesn&#039;t threaten users of any other currency: if a Bitcoin user loses his wallet, his money is gone forever, unless he finds it again. And not just to him; it&#039;s gone completely out of circulation, rendered utterly inaccessible to anyone. As people will lose their wallets, the total number of Bitcoins will slowly decrease.&lt;br /&gt;
&lt;br /&gt;
Therefore, Bitcoin seems to be faced with a unique problem. Whereas most currencies inflate over time, Bitcoin will mostly likely do just the opposite. Time will see the irretrievable loss of an ever-increasing number of Bitcoins. An already small number will be permanently whittled down further and further. And as there become fewer and fewer Bitcoins, the laws of supply and demand suggest that their value will probably continually rise.&lt;br /&gt;
&lt;br /&gt;
Thus Bitcoin is bound to once again stray into mysterious territory, because no one exactly knows what happens to a currency that grows continually more valuable. Many economists claim that a low level of inflation is a good thing for a currency, but nobody is quite sure about what might happens to one that continually deflates. Although deflation could hardly be called a rare phenomenon, steady, constant deflation is unheard of.  There may be a lot of speculation, no one has any hard data to back up their claims.&lt;br /&gt;
&lt;br /&gt;
That being said, there is a mechanism in place to combat the obvious consequences.  Extreme deflation would render most currencies highly impractical: if a single Canadian dollar could suddenly buy the holder a car, how would one go about buying bread or candy?  Even pennies would fetch more than a person could carry. Bitcoin, however, offers a simple and stylish solution: infinite divisibility.  Bitcoins can be divided up and trade into as small of pieces as one wants, so no matter how valuable Bitcoins become, one can trade them in practical quantities.  &lt;br /&gt;
&lt;br /&gt;
In fact, infinite divisibility should allow Bitcoins to function in cases of extreme wallet loss.  Even if, in the far future, so many people have lost their wallets that only a single Bitcoin, or a fraction of one, remains, Bitcoin should continue to function just fine. No one can claim to be sure what is going to happen, but deflation may prove to present a smaller threat than many expect.&lt;br /&gt;
&lt;br /&gt;
For more information, see the [[Deflationary spiral]] page.&lt;br /&gt;
&lt;br /&gt;
=== Daca cineva ar cumpara fiecare bitcoin care a fost creat? ===&lt;br /&gt;
Bitcoin markets are competitive -- meaning the price of a bitcoin will rise or fall depending on supply and demand at certain price levels.  Only a fraction of bitcoins issued to date are found on the exchange markets for sale.  So even though technically a buyer with lots of money could buy all the bitcoins offered for sale, unless those holding the rest of the bitcoins offer them for sale as well, even the wealthiest, most determined buyer can&#039;t get at them.&lt;br /&gt;
&lt;br /&gt;
Additionally, new currency continues to be issued daily and will continue to do so for decades though over time the rate at which they are issued declines to insignificant levels.  Those who are mining aren&#039;t obligated to sell their bitcoins so not all bitcoins will make it to the markets even.&lt;br /&gt;
&lt;br /&gt;
This situation doesn&#039;t suggest, however, that the markets aren&#039;t vulnerable to price manipulation.  It doesn&#039;t take significant amounts of money to move the market price up or down and thus Bitcoin remains a volatile asset.&lt;br /&gt;
&lt;br /&gt;
===Daca cineva creaza un nou lant de blocuri(block chain), sau o noua moneda digitala care scoate Bitcoinul din uz?===&lt;br /&gt;
&lt;br /&gt;
That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
&lt;br /&gt;
As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
&lt;br /&gt;
A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
&lt;br /&gt;
Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
&lt;br /&gt;
A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
&lt;br /&gt;
A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
&lt;br /&gt;
This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoinul susceptibil manipularii valorii sale? ===&lt;br /&gt;
&lt;br /&gt;
The current low market cap of Bitcoin means that any investor with deep enough pockets can significantly change/manipulate the rate. Is this a problem?&lt;br /&gt;
&lt;br /&gt;
This is only a problem if you are investing in Bitcoin for short period of time. A manipulator can&#039;t change the fundamentals, and over a period of 5-10 years they will win over any short term manipulations.&lt;br /&gt;
&lt;br /&gt;
==Efectuarea si primirea de plati==&lt;br /&gt;
&lt;br /&gt;
=== De ce trebuie sa astept 10 minute inainte sa pot cheltui banii primiti? ===&lt;br /&gt;
&lt;br /&gt;
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. &lt;br /&gt;
&lt;br /&gt;
You can see how long all other recent transactions have taken here: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
&lt;br /&gt;
[[Blocks]] (shown as &amp;quot;confirmations&amp;quot; in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it&#039;s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!&lt;br /&gt;
&lt;br /&gt;
Ten minutes was specifically chosen by [[Satoshi]] as a tradeoff between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. For a more technical explanation, see Satoshi&#039;s [http://www.bitcoin.org/bitcoin.pdf original technical paper].&lt;br /&gt;
&lt;br /&gt;
[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
&lt;br /&gt;
=== Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
YES, you do, IF the transaction is non-recourse. The Bitcoin reference software does not display transactions as confirmed until six blocks have passed (confirmations). As transactions are burred in the chain they become increasingly non-reversible but are very reversible before the first confirmation. Two to six confirmations are recommended for non-recourse situations depending on the value of the transactions involved.&lt;br /&gt;
&lt;br /&gt;
When people ask this question they are usually thinking about applications like supermarkets.  This generally is a recourse situation: if somebody tries to double-spend on a face-to-face transaction it might work a few times, but probabalistically speaking eventually one of the double-spends will get noticed, and the penalty for shoplifting charges in most localities is calibrated to be several times worse than the proceeds of a single shoplifting event.&lt;br /&gt;
&lt;br /&gt;
Double-spends might be a concern for something like a snack machine in a low-traffic area with no nearby security cameras.  Such a machine shouldn&#039;t honor 0-confirmation payments, and should instead use some other mechanism of clearing Bitcoin or validating transactions against reversal, see the wiki article [[Myths#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|here]] for alternatives.&lt;br /&gt;
&lt;br /&gt;
Applications that require immediate payment processing, like supermarkets or snack machines, need to manage the risks. Here is one way to reverse an unconfirmed payment:&lt;br /&gt;
&lt;br /&gt;
A [[Double-spending#Finney_attack|Finney attack]], in which an attacker mines a block containing a movement of some coins back to themselves. Once they find a block solution, they quickly go to a merchant and make a purchase, then broadcast the block, thus taking back the coins. This attack is a risk primarily for goods that are dispatched immediately, like song downloads or currency trades. Because the attacker can&#039;t choose the time of the attack, it isn&#039;t a risk for merchants such as supermarkets where you can&#039;t choose exactly when to pay (due to queues, etc). The attack can fail if somebody else finds a block containing the purchasing transaction before you release your own block, therefore, merchants can reduce but not eliminate the risk by making purchasers wait some length of time that&#039;s less than a confirm.&lt;br /&gt;
&lt;br /&gt;
Because pulling off this attack is not trivial, merchants who need to sell things automatically and instantly are most likely to just price the cost of reversal fraud in, or use insurance.&lt;br /&gt;
&lt;br /&gt;
=== I was sent some bitcoins and they haven&#039;t arrived yet! Where are they? ===&lt;br /&gt;
&lt;br /&gt;
Don&#039;t panic!  There are a number of reasons why your bitcoins might not show up yet, and a number of ways to diagnose them.  &lt;br /&gt;
&lt;br /&gt;
The latest version of the Bitcoin-Qt client tells you how far it has yet to go in downloading the blockchain.  Hover over the icon in the bottom right corner of the client to learn your client&#039;s status.&lt;br /&gt;
&lt;br /&gt;
If it has not caught up then it&#039;s possible that your transaction hasn&#039;t been included in a block yet.  &lt;br /&gt;
&lt;br /&gt;
You can check pending transactions in the network by going [http://blockchain.info here] and then searching for your address.  If the transaction is listed here then it&#039;s a matter of waiting until it gets included in a block before it will show in your client.  &lt;br /&gt;
&lt;br /&gt;
If the transaction is based on a coin that was in a recent transaction then it could be considered a low priority transaction. Transfers can take longer if the transaction fee paid was not high enough.  If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.&lt;br /&gt;
&lt;br /&gt;
=== Why does my Bitcoin address keep changing? ===&lt;br /&gt;
&lt;br /&gt;
Whenever the address listed in &amp;quot;Your address&amp;quot; receives a transaction, Bitcoin replaces it with a new address. This is meant to encourage you to use a new address for every transaction, which enhances [[anonymity]]. All of your old addresses are still usable: you can see them in &#039;&#039;Settings -&amp;gt; Your Receiving Addresses&#039;&#039;.&lt;br /&gt;
&lt;br /&gt;
===How much will the transaction fee be?===&lt;br /&gt;
&lt;br /&gt;
Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
&lt;br /&gt;
The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
&lt;br /&gt;
A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
&lt;br /&gt;
Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
&lt;br /&gt;
As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
&lt;br /&gt;
=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
&lt;br /&gt;
If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
&lt;br /&gt;
=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
&lt;br /&gt;
The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
&lt;br /&gt;
In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
&lt;br /&gt;
When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
&lt;br /&gt;
If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
&lt;br /&gt;
==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
&lt;br /&gt;
If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
&lt;br /&gt;
=== How does the peer finding mechanism work? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
&lt;br /&gt;
==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
&lt;br /&gt;
Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
&lt;br /&gt;
===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
&lt;br /&gt;
===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Help==&lt;br /&gt;
===I&#039;d like to learn more.  Where can I get help?===&lt;br /&gt;
&lt;br /&gt;
* Read the [[Introduction|introduction to bitcoin]] &lt;br /&gt;
* See the videos, podcasts, and blog posts from the [[Press]]&lt;br /&gt;
* Read and post on the [[:Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]&lt;br /&gt;
* Chat on one of the [[:Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels&lt;br /&gt;
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works&lt;br /&gt;
* Ask questions on the [http://bitcoin.stackexchange.com Bitcoin Stack Exchange]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=75</id>
		<title>Intrebari Frecvente</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Intrebari_Frecvente&amp;diff=75"/>
		<updated>2013-05-24T07:38:53Z</updated>

		<summary type="html">&lt;p&gt;8fold: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Aici veți găsi răspunsuri la majoritatea întrebărilor frecvente.&lt;br /&gt;
&lt;br /&gt;
== General ==&lt;br /&gt;
=== Ce sunt bitcoinii? ===&lt;br /&gt;
Bitcoin-ul este unitatea de monedă a sistemului Bitcoin. O prescurtare utilizată în mod obișnuit pentru această monedă este &amp;quot;BTC&amp;quot;, pentru a se referi la un preț sau cantitate (de exemplu: &amp;quot;100 BTC&amp;quot;).&lt;br /&gt;
Există astfel de lucruri ca [[Bitcoin fizic]], dar în cele din urmă, un Bitcoin este doar un număr asociat cu o [[Address | Bitcoin Address]]. &lt;br /&gt;
Un Bitcoin fizic este pur și simplu un obiect, cum ar fi o monedă, cu numărul atent integrat în interior. &lt;br /&gt;
A se vedea, de asemenea, o [[Introducere | introducere ușoară]] pentru Bitcoin.&lt;br /&gt;
&lt;br /&gt;
=== Cum fac rost de bitcoini? ===&lt;br /&gt;
&lt;br /&gt;
There are a variety of ways to acquire bitcoins:&lt;br /&gt;
&lt;br /&gt;
* Accept bitcoins as payment for goods or services.&lt;br /&gt;
* The most common way to buy bitcoins are the [[Buying bitcoins|Bitcoin Exchanges]]&lt;br /&gt;
* There are several services where you can [[Buying_Bitcoins_(the_noob_version)|trade them]] for traditional currency.&lt;br /&gt;
* Find someone to trade cash for bitcoins in-person through a [https://en.bitcoin.it/wiki/Category:Directories local directory].&lt;br /&gt;
* Participate in a [[Pooled mining|mining pool]].&lt;br /&gt;
* If you have a lot of mining hardware, you can solo mine and attempt to create a new [[block]] (currently yields 25 bitcoins plus transaction fees).&lt;br /&gt;
* Visit sites that provide [[Trade#Free_Samples_and_Offers|free samples and offers]].&lt;br /&gt;
&lt;br /&gt;
===Bitcoin garanteaza un flux gratis de bani?===&lt;br /&gt;
&lt;br /&gt;
Since Bitcoin is a new technology, what it is and how it works may be initially unclear.  Bitcoin is sometimes presented as being one of three things:&lt;br /&gt;
&amp;lt;ol style=&amp;quot;list-style-type: upper-alpha;&amp;quot;&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;Some sort of online &#039;get-rich-quick&#039; scam.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A loophole in the market economy, the installation of which guarantees a steady influx of cash.&amp;lt;/li&amp;gt;&lt;br /&gt;
  &amp;lt;li&amp;gt;A sure investment that will almost certainly yield a profit.&amp;lt;/li&amp;gt;&lt;br /&gt;
&amp;lt;/ol&amp;gt;&lt;br /&gt;
In fact, none of the above are true.  Let&#039;s look at them independently.&lt;br /&gt;
&lt;br /&gt;
;Is Bitcoin a &#039;get-rich-quick&#039; scheme?&lt;br /&gt;
:If you&#039;ve spent much time on the Internet, you&#039;ve probably seen ads for many &#039;get-rich-quick&#039; schemes. These ads usually promise huge profits for a small amounts of easy work.  Such schemes are usually pyramid/matrix-style schemes that make money from their own employees and offer nothing of any real value.  Most convince one to buy packages that will make them earn hundreds a day, which in fact  have the buyer distribute more such ads, and make minute profits.&lt;br /&gt;
&lt;br /&gt;
:Bitcoin is in no way similar to these schemes. Bitcoin doesn&#039;t promise windfall profits. There is no way for the developers to make money from your involvement or to take money from you. That bitcoins are nearly impossible to acquire without the owner&#039;s consent represents one of its greatest strengths.  Bitcoin is an experimental, virtual currency that may succeed or may fail. None of its developers expect to get rich off of it. &lt;br /&gt;
&lt;br /&gt;
:A more detailed answer to this question can be found [http://bitcointalk.org/?topic=7815.0 here].&lt;br /&gt;
&lt;br /&gt;
;Will I make money by installing the client?&lt;br /&gt;
:Most people who use Bitcoin don&#039;t earn anything by doing so, and the default client has no built-in way to earn Bitcoins.  A small minority of people with dedicated, high-performance hardware do earn some Bitcoins by &amp;quot;&#039;&#039;mining&#039;&#039;&amp;quot; (generating new bitcoins, see [[#What is mining?|What is mining?]]) with special software, but joining Bitcoin shouldn&#039;t be construed as being the road to riches.  Most Bitcoin users get involved because they find the project conceptually interesting and don&#039;t earn anything by doing so.  This is also why you won&#039;t find much speculation about the political or economic repercussions of Bitcoin anywhere on this site: Bitcoin developers owe their dedication to the project&#039;s intellectual yieldings more than to those of a monetary nature.  Bitcoin is still taking its first baby steps; it may go on to do great things but right now it only has something to offer those chasing conceptually interesting projects or bleeding edge technology.&lt;br /&gt;
&lt;br /&gt;
;As an investment, is Bitcoin a sure thing?&lt;br /&gt;
:Bitcoin is a new and interesting electronic currency, the value of which is not backed by any single government or organization.  Like other currencies, it is worth something partly because people are willing to trade it for goods and services. Its exchange rate fluctuates continuously, and sometimes wildly. It lacks wide acceptance and is vulnerable to manipulation by parties with modest funding. Security incidents such as website and account compromise may trigger major sell-offs. Other fluctuations can build into positive feedback loops and cause much larger exchange rate fluctuations. Anyone who puts money into Bitcoin should understand the risk they are taking and consider it a high-risk currency. Later, as Bitcoin becomes better known and more widely accepted, it may stabilize, but for the time being it is unpredictable. Any investment in Bitcoin should be done carefully and with a clear plan to manage the risk.&lt;br /&gt;
&lt;br /&gt;
=== Pot cumpara bitcoini cu Paypal? ===&lt;br /&gt;
&lt;br /&gt;
It is possible to buy [[physical bitcoins]] with PayPal but it is otherwise difficult and/or expensive to do so for non-physical bitcoins, because of significant risk to the seller. &lt;br /&gt;
&lt;br /&gt;
While it is possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most exchanges do not allow funding through PayPal. This is due to repeated cases where someone pays for bitcoins with Paypal, receives their bitcoins, and then fraudulently complains to Paypal that they never received their purchase. PayPal often sides with the fraudulent buyer in this case, which means any seller needs to cover that risk with higher fees or refuse to accept PayPal altogether.&lt;br /&gt;
&lt;br /&gt;
Buying Bitcoins from individuals this way is still possible, but requires the seller to have some trust that the buyer will not file a claim with PayPal to reverse the payment.&lt;br /&gt;
&lt;br /&gt;
=== Unde pot gasi un forum dedicat discutiilor despre Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Please visit the  [[Bitcoin:Community_portal#Bitcoin_Community_Forums_on_various_platforms|Community Portal]] for links to Bitcoin-related forums.&lt;br /&gt;
&lt;br /&gt;
=== Cum sunt bitcoinii creati? ===&lt;br /&gt;
&lt;br /&gt;
[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]&lt;br /&gt;
New bitcoins are generated by the network through the process of &amp;quot;[[#What is mining?|&#039;&#039;mining&#039;&#039;]]&amp;quot;. In a process that is similar to a continuous raffle draw, mining nodes on the network are awarded bitcoins each time they find the solution to a certain mathematical problem (and thereby create a new [[block]]). Creating a block is a [[proof of work]] with a difficulty that varies with the overall strength of the network.  The reward for solving a block is [[Controlled Currency Supply|automatically adjusted]] so that roughly every four years of operation of the Bitcoin network, half the amount of bitcoins created in the prior 4 years are created. {{formatnum:10500000}} bitcoins were created in the first 4 (approx.) years from January 2009 to November 2012.  Every four years thereafter this amount halves, so it will be {{formatnum:5250000}} over years 4-8, {{formatnum:2625000}} over years 8-12, and so on. Thus the total number of bitcoins in existence will never exceed {{formatnum:21000000}}. See [[Controlled Currency Supply]].&lt;br /&gt;
&lt;br /&gt;
Blocks are [[Mining|mined]] every 10 minutes, on average and for the first four years ({{formatnum:210000}} blocks) each block included 50 new bitcoins.  As the amount of processing power directed at mining changes, the difficulty of creating new bitcoins changes.  This difficulty factor is calculated every 2016 blocks and is based upon the time taken to generate the previous 2016 blocks. See [[Mining]].&lt;br /&gt;
&lt;br /&gt;
=== Care este numarul total de bitcoini?  ===&lt;br /&gt;
&lt;br /&gt;
[http://blockexplorer.com/q/totalbc Current count]. Also see [https://blockchain.info/charts/total-bitcoins Total bitcoins in circulation chart]&lt;br /&gt;
&lt;br /&gt;
The number of blocks times the coin value of a block is the number of coins in existence. The coin value of a block is 50 BTC for each of the first {{formatnum:210000}} blocks, 25 BTC for the next {{formatnum:210000}} blocks, then 12.5 BTC, 6.25 BTC and so on.&lt;br /&gt;
&lt;br /&gt;
=== Cat de divizibili sunt bitcoinii?  ===&lt;br /&gt;
&lt;br /&gt;
A bitcoin can be divided down to 8 decimal places. Therefore, 0.00000001 BTC is the smallest amount that can be handled in a transaction. If necessary, the protocol and related software can be modified to handle even smaller amounts.&lt;br /&gt;
&lt;br /&gt;
=== Cum se numesc denominarile bitcoinului? ===&lt;br /&gt;
&lt;br /&gt;
There is a lot of discussion about the naming of these fractions of bitcoins. The leading candidates are:&lt;br /&gt;
&lt;br /&gt;
* 1 BTC = 1 bitcoin&lt;br /&gt;
* 0.01 BTC = 1 cBTC = 1 centibitcoin (also referred to as bitcent)&lt;br /&gt;
* 0.001 BTC = 1 mBTC = 1 millibitcoin (also referred to as mbit (pronounced em-bit) or millibit or even bitmill)&lt;br /&gt;
* 0.000 001 BTC = 1 μBTC = 1 microbitcoin (also referred to as ubit (pronounced yu-bit) or microbit)&lt;br /&gt;
&lt;br /&gt;
The above follows the accepted international SI prefixes for hundredths, thousandths, and millionths. There are many arguments against the special case of 0.01 BTC since it is unlikely to represent anything meaningful as the Bitcoin economy grows (it certainly won&#039;t be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as &amp;quot;cent&amp;quot;, &amp;quot;nickel&amp;quot;, &amp;quot;dime&amp;quot;, &amp;quot;pence&amp;quot;, &amp;quot;pound&amp;quot;, &amp;quot;kopek&amp;quot; and so on are to be discouraged; this is a worldwide currency.&lt;br /&gt;
&lt;br /&gt;
One exception is the &amp;quot;satoshi&amp;quot; which is smallest denomination currently possible &lt;br /&gt;
&lt;br /&gt;
* 0.000 000 01 BTC = 1 satoshi (pronounced sa-toh-shee)&lt;br /&gt;
which is so named in honour of Satoshi Nakamoto, the pseudonym of the inventor of Bitcoin.&lt;br /&gt;
&lt;br /&gt;
For an overview of all defined units of Bitcoin (including less common and niche units), see [[Units]].&lt;br /&gt;
&lt;br /&gt;
Further discussion on this topic can be found on the forums here:&lt;br /&gt;
&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=14438.msg195287#msg195287 We need names]&lt;br /&gt;
* [https://bitcointalk.org/index.php?topic=8282.0 What to call 0.001 BTC]&lt;br /&gt;
&lt;br /&gt;
=== Cum functioneaza injumatatirea cand numarul devine foarte mic? ===&lt;br /&gt;
&lt;br /&gt;
Eventually the reward will go from 0.00000001 BTC to zero and no more bitcoins will be created.  &lt;br /&gt;
&lt;br /&gt;
The block reward calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by two and rounded down. The integer is equal to the value in BTC * 100,000,000 since internally in the reference client software, all Bitcoin balances and values are stored as unsigned integers.&lt;br /&gt;
&lt;br /&gt;
With an initial block reward of 50 BTC, it will take many 4-year periods for the block reward to reach zero.&lt;br /&gt;
&lt;br /&gt;
=== Cat timp va dura pana vor fi generate toate monezile? ===&lt;br /&gt;
&lt;br /&gt;
The last block that will generate coins will be block #6,929,999 which should be generated at or near the year 2140. The total number of coins in circulation will then remain static at 20,999,999.9769 BTC.&lt;br /&gt;
&lt;br /&gt;
Even if the allowed precision is expanded from the current 8 decimals, the total BTC in circulation will always be slightly below 21 million (assuming everything else stays the same). For example, with 16 decimals of precision, the end total would be 20,999,999.999999999496 BTC.&lt;br /&gt;
&lt;br /&gt;
=== Daca nu mai sunt generate monezi, se vor mai crea block-uri? ===&lt;br /&gt;
&lt;br /&gt;
Absolutely!  Even before the creation of coins ends, the use of [[transaction fee|transaction fees]] will likely make creating new blocks more valuable from the fees than the new coins being created.  When coin generation ends, these fees will sustain the ability to use bitcoins and the Bitcoin network. There is no practical limit on the number of blocks that will be mined in the future.&lt;br /&gt;
&lt;br /&gt;
=== Dar daca nu mai sunt generate monezi, ce se intampla cand se pierd bitcoini? Nu ar fi o problema? ===&lt;br /&gt;
&lt;br /&gt;
Because of the law of supply and demand, when fewer bitcoins are available the ones that are left will be in higher demand, and therefore will have a higher value. So, as Bitcoins are lost, the remaining bitcoins will eventually increase in value to compensate. As the value of a bitcoin increases, the number of bitcoins required to purchase an item &#039;&#039;&#039;de&#039;&#039;&#039;creases. This is a [[Deflationary spiral|deflationary economic model]]. As the average transaction size reduces, transactions will probably be denominated in sub-units of a bitcoin such as millibitcoins (&amp;quot;Millies&amp;quot;) or microbitcoins (&amp;quot;Mikes&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
The Bitcoin protocol uses a base unit of one hundred-millionth of a Bitcoin (&amp;quot;a Satoshi&amp;quot;), but unused bits are available in the protocol fields that could be used to denote even smaller subdivisions.&lt;br /&gt;
&lt;br /&gt;
=== Daca fiecare tranzactie este emisa prin retea, atunci Bitcoin este scalabil? ===&lt;br /&gt;
The Bitcoin protocol allows lightweight clients that can use Bitcoin without downloading the entire transaction history. As traffic grows and this becomes more critical, implementations of the concept will be developed. Full network nodes will at some point become a more specialized service.&lt;br /&gt;
&lt;br /&gt;
With some modifications to the software, full Bitcoin nodes could easily keep up with both VISA and MasterCard combined, using only fairly modest hardware (a single high end server by todays standards). It is worth noting that the MasterCard network is structured somewhat like Bitcoin itself - as a peer to peer broadcast network.&lt;br /&gt;
&lt;br /&gt;
Learn more about [[Scalability]].&lt;br /&gt;
&lt;br /&gt;
==Economie==&lt;br /&gt;
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===&lt;br /&gt;
Bitcoins have value because they are useful and because they are [[Controlled Currency Supply|scarce]]. As they are accepted by more merchants, their value will [http://en.wikipedia.org/wiki/Sticky_%28economics%29 stabilize]. See the [[Trade|list of Bitcoin-accepting sites]].&lt;br /&gt;
&lt;br /&gt;
When we say that a currency is backed up by gold, we mean that there&#039;s a promise in place that you can exchange the currency for gold. Bitcoins, like dollars and euros, are not backed up by anything except the variety of merchants that accept them.&lt;br /&gt;
&lt;br /&gt;
It&#039;s a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn&#039;t equal value – hiring 1,000 men to shovel a big hole in the ground may be costly, but not valuable. Also, even though scarcity is a critical requirement for a useful currency, it alone doesn&#039;t make anything valuable. For example, your fingerprints are scarce, but that doesn&#039;t mean they have any exchange value.&lt;br /&gt;
&lt;br /&gt;
Alternatively it needs to be added that while the law of supply and demand applies it does not guarantee value of Bitcoins in the future.  If confidence in Bitcoins is lost then it will not matter that the supply can no longer be increased, the demand will fall off with all holders trying to get rid of their coins.  An example of this can be seen in cases of state currencies, in cases when the state in question dissolves and so no new supply of the currency is available (the central authority managing the supply is gone), however the demand for the currency falls sharply because confidence in its purchasing power disappears.  Of-course Bitcoins do not have such central authority managing the supply of the coins, but it does not prevent confidence from eroding due to other situations that are not necessarily predictable.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o bula? ===&lt;br /&gt;
Yes, in the same way as the euro and dollar are. They only have value in exchange and have no inherent value. If everyone suddenly stopped accepting your dollars, euros or bitcoins, the &amp;quot;bubble&amp;quot; would burst and their value would drop to zero. But that is unlikely to happen: even in Somalia, where the government collapsed 20 years ago, [http://en.wikipedia.org/wiki/Somali_shilling Somali shillings] are still accepted as payment.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoin o schema piramidala/Ponzi? ===&lt;br /&gt;
In a Ponzi Scheme, the founders persuade investors that they’ll profit. Bitcoin does not make such a guarantee. There is no central entity, just individuals building an economy.&lt;br /&gt;
&lt;br /&gt;
A ponzi scheme is a zero sum game. Early adopters can only profit at the expense of late adopters. Bitcoin has possible win-win outcomes. Early adopters profit from the rise in value. Late adopters, and indeed, society as a whole, benefit from the usefulness of a stable, fast, inexpensive, and widely accepted p2p currency.&lt;br /&gt;
&lt;br /&gt;
The fact that early adopters benefit more doesn&#039;t alone make anything a Ponzi scheme. All good investments in successful companies have this quality.&lt;br /&gt;
&lt;br /&gt;
=== Nu cumva Bitcoin favorizeaza pe nedrept investitorii initiali? ===&lt;br /&gt;
Early adopters have a large number of bitcoins now because they took a risk and invested resources in an unproven technology. By so doing, they have helped Bitcoin become what it is now and what it will be in the future (hopefully, a ubiquitous decentralized digital currency). It is only fair they will reap the benefits of their successful investment.&lt;br /&gt;
&lt;br /&gt;
In any case, any bitcoin generated will probably change hands dozens of time as a medium of exchange, so the profit made from the initial distribution will be insignificant compared to the total commerce enabled by Bitcoin.&lt;br /&gt;
&lt;br /&gt;
Since the pricing of Bitcoins has fallen greatly from its June 2011 peak, prices today are much more similar to those enjoyed by many early adopters.  Those who are buying Bitcoins today likely believe that Bitcoin will grow significantly in the future.  Setting aside the brief opportunity to have sold Bitcoins at the June 2011 peak enjoyed by few, the early-adopter window is arguably still open.&lt;br /&gt;
&lt;br /&gt;
===Pierderea de portofele si faptul ca numarul de bitcoini este finit nu ar cauza deflatie excesiva, distrugand Bitcoinul? ===&lt;br /&gt;
Worries about Bitcoin being destroyed by deflation are not entirely unfounded.  Unlike most currencies, which experience inflation as their founding institutions create more and more units, Bitcoin will likely experience gradual deflation with the passage of time.  Bitcoin is unique in that only a small amount of units will ever be produced (twenty-one million to be exact), this number has been known since the project&#039;s inception, and the units are created at a predictable rate.&lt;br /&gt;
&lt;br /&gt;
Also, Bitcoin users are faced with a danger that doesn&#039;t threaten users of any other currency: if a Bitcoin user loses his wallet, his money is gone forever, unless he finds it again. And not just to him; it&#039;s gone completely out of circulation, rendered utterly inaccessible to anyone. As people will lose their wallets, the total number of Bitcoins will slowly decrease.&lt;br /&gt;
&lt;br /&gt;
Therefore, Bitcoin seems to be faced with a unique problem. Whereas most currencies inflate over time, Bitcoin will mostly likely do just the opposite. Time will see the irretrievable loss of an ever-increasing number of Bitcoins. An already small number will be permanently whittled down further and further. And as there become fewer and fewer Bitcoins, the laws of supply and demand suggest that their value will probably continually rise.&lt;br /&gt;
&lt;br /&gt;
Thus Bitcoin is bound to once again stray into mysterious territory, because no one exactly knows what happens to a currency that grows continually more valuable. Many economists claim that a low level of inflation is a good thing for a currency, but nobody is quite sure about what might happens to one that continually deflates. Although deflation could hardly be called a rare phenomenon, steady, constant deflation is unheard of.  There may be a lot of speculation, no one has any hard data to back up their claims.&lt;br /&gt;
&lt;br /&gt;
That being said, there is a mechanism in place to combat the obvious consequences.  Extreme deflation would render most currencies highly impractical: if a single Canadian dollar could suddenly buy the holder a car, how would one go about buying bread or candy?  Even pennies would fetch more than a person could carry. Bitcoin, however, offers a simple and stylish solution: infinite divisibility.  Bitcoins can be divided up and trade into as small of pieces as one wants, so no matter how valuable Bitcoins become, one can trade them in practical quantities.  &lt;br /&gt;
&lt;br /&gt;
In fact, infinite divisibility should allow Bitcoins to function in cases of extreme wallet loss.  Even if, in the far future, so many people have lost their wallets that only a single Bitcoin, or a fraction of one, remains, Bitcoin should continue to function just fine. No one can claim to be sure what is going to happen, but deflation may prove to present a smaller threat than many expect.&lt;br /&gt;
&lt;br /&gt;
For more information, see the [[Deflationary spiral]] page.&lt;br /&gt;
&lt;br /&gt;
=== Daca cineva ar cumpara fiecare bitcoin care a fost creat? ===&lt;br /&gt;
Bitcoin markets are competitive -- meaning the price of a bitcoin will rise or fall depending on supply and demand at certain price levels.  Only a fraction of bitcoins issued to date are found on the exchange markets for sale.  So even though technically a buyer with lots of money could buy all the bitcoins offered for sale, unless those holding the rest of the bitcoins offer them for sale as well, even the wealthiest, most determined buyer can&#039;t get at them.&lt;br /&gt;
&lt;br /&gt;
Additionally, new currency continues to be issued daily and will continue to do so for decades though over time the rate at which they are issued declines to insignificant levels.  Those who are mining aren&#039;t obligated to sell their bitcoins so not all bitcoins will make it to the markets even.&lt;br /&gt;
&lt;br /&gt;
This situation doesn&#039;t suggest, however, that the markets aren&#039;t vulnerable to price manipulation.  It doesn&#039;t take significant amounts of money to move the market price up or down and thus Bitcoin remains a volatile asset.&lt;br /&gt;
&lt;br /&gt;
===Daca cineva creaza un nou lant de blocuri(block chain), sau o noua moneda digitala care scoate Bitcoinul din uz?===&lt;br /&gt;
&lt;br /&gt;
That the block chain cannot be easily forked represents one of the central security mechanisms of Bitcoin.  Given the choice between two block chains, a Bitcoin miner always chooses the longer one - that is to say, the one with the more complex hash.  Thusly, it ensures that each user can only spend their bitcoins once, and that no user gets ripped off.&lt;br /&gt;
&lt;br /&gt;
As a consequence of the block chain structure, there may at any time be many different sub-branches, and the possibility always exists of a transaction being over-written by the longest branch, if it has been recorded in a shorter one.  The older a transaction is though, the lower its chances of being over-written, and the higher of becoming permanent.  Although the block chain prevents one from spending more Bitcoins than one has, it means that transactions can be accidentally nullified.  &lt;br /&gt;
&lt;br /&gt;
A new block chain would leave the network vulnerable to [[double-spending|double-spend]] attacks.  However, the creation of a viable new chain presents considerable difficulty, and the possibility does not present much of a risk.&lt;br /&gt;
&lt;br /&gt;
Bitcoin will always choose the longer Block Chain and determines the relative length of two branches by the complexities of their hashes.  Since the hash of each new block is made from that of the block preceding it, to create a block with a more complex hash, one must be prepared to do more computation than has been done by the entire Bitcoin network from the fork point up to the newest of the blocks one is trying to supersede.  Needless to say, such an undertaking would require a very large amount of processing power and since Bitcoin is continually growing and expanding, it will likely only require more with the passage of time.&lt;br /&gt;
&lt;br /&gt;
A much more distinct and real threat to the Bitcoin use is the development of other, superior virtual currencies, which could supplant Bitcoin and render it obsolete and valueless.&lt;br /&gt;
&lt;br /&gt;
A great deal of careful thought and ingenuity has gone into the development of Bitcoin, but it is the first of its breed, a prototype, and vulnerable to more highly-evolved competitors. At present, any threatening rivals have yet to rear their heads; Bitcoin remains the first and foremost private virtual currency, but we can offer no guarantees that it will retain that position.  It would certainly be in keeping with internet history for a similar system built from the same principles to supersede and cast Bitcoin into obsolescence, after time had revealed its major shortcomings.  Friendster and Myspace suffered similar fates at the hand of Facebook, Napster was ousted by Limeware, Bearshare and torrent applications, and Skype has all but crushed the last few disciples of the Microsoft Messenger army.  &lt;br /&gt;
&lt;br /&gt;
This may sound rather foreboding, so bear in mind that the introduction of new and possibly better virtual currencies will not necessarily herald Bitcoin&#039;s demise.  If Bitcoin establishes itself sufficiently firmly before the inception of the next generation of private, online currencies so as to gain widespread acceptance and general stability, future currencies may pose little threat even if they can claim superior design.  This is known as the network effect.&lt;br /&gt;
&lt;br /&gt;
=== Este Bitcoinul susceptibil manipularii valorii sale? ===&lt;br /&gt;
&lt;br /&gt;
The current low market cap of Bitcoin means that any investor with deep enough pockets can significantly change/manipulate the rate. Is this a problem?&lt;br /&gt;
&lt;br /&gt;
This is only a problem if you are investing in Bitcoin for short period of time. A manipulator can&#039;t change the fundamentals, and over a period of 5-10 years they will win over any short term manipulations.&lt;br /&gt;
&lt;br /&gt;
==Efectuarea si primirea de plati==&lt;br /&gt;
&lt;br /&gt;
=== De ce trebuie sa astept 10 minute inainte sa pot cheltui banii primiti? ===&lt;br /&gt;
&lt;br /&gt;
10 minutes is the average time taken to find a block. It can be significantly more or less time than that depending on luck; 10 minutes is simply the average case. &lt;br /&gt;
&lt;br /&gt;
You can see how long all other recent transactions have taken here: [http://bitcoinstats.org/ BitcoinStats.org]. &lt;br /&gt;
&lt;br /&gt;
[[Blocks]] (shown as &amp;quot;confirmations&amp;quot; in the GUI) are how the Bitcoin achieves consensus on who owns what. Once a block is found everyone agrees that you now own those coins, so you can spend them again. Until then it&#039;s possible that some network nodes believe otherwise, if somebody is attempting to defraud the system by reversing a transaction. The more confirmations a transaction has, the less risk there is of a reversal. Only 6 blocks or 1 hour is enough to make reversal computationally impractical. This is dramatically better than credit cards which can see chargebacks occur up to three months after the original transaction!&lt;br /&gt;
&lt;br /&gt;
Ten minutes was specifically chosen by [[Satoshi]] as a tradeoff between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. For a more technical explanation, see Satoshi&#039;s [http://www.bitcoin.org/bitcoin.pdf original technical paper].&lt;br /&gt;
&lt;br /&gt;
[[File:TransactionConfirmationTimesExample.PNG]]&lt;br /&gt;
&lt;br /&gt;
=== Do you have to wait until my transactions are confirmed in order to buy or sell things with Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
YES, you do, IF the transaction is non-recourse. The Bitcoin reference software does not display transactions as confirmed until six blocks have passed (confirmations). As transactions are burred in the chain they become increasingly non-reversible but are very reversible before the first confirmation. Two to six confirmations are recommended for non-recourse situations depending on the value of the transactions involved.&lt;br /&gt;
&lt;br /&gt;
When people ask this question they are usually thinking about applications like supermarkets.  This generally is a recourse situation: if somebody tries to double-spend on a face-to-face transaction it might work a few times, but probabalistically speaking eventually one of the double-spends will get noticed, and the penalty for shoplifting charges in most localities is calibrated to be several times worse than the proceeds of a single shoplifting event.&lt;br /&gt;
&lt;br /&gt;
Double-spends might be a concern for something like a snack machine in a low-traffic area with no nearby security cameras.  Such a machine shouldn&#039;t honor 0-confirmation payments, and should instead use some other mechanism of clearing Bitcoin or validating transactions against reversal, see the wiki article [[Myths#Point_of_sale_with_bitcoins_isn.27t_possible_because_of_the_10_minute_wait_for_confirmation|here]] for alternatives.&lt;br /&gt;
&lt;br /&gt;
Applications that require immediate payment processing, like supermarkets or snack machines, need to manage the risks. Here is one way to reverse an unconfirmed payment:&lt;br /&gt;
&lt;br /&gt;
A [[Double-spending#Finney_attack|Finney attack]], in which an attacker mines a block containing a movement of some coins back to themselves. Once they find a block solution, they quickly go to a merchant and make a purchase, then broadcast the block, thus taking back the coins. This attack is a risk primarily for goods that are dispatched immediately, like song downloads or currency trades. Because the attacker can&#039;t choose the time of the attack, it isn&#039;t a risk for merchants such as supermarkets where you can&#039;t choose exactly when to pay (due to queues, etc). The attack can fail if somebody else finds a block containing the purchasing transaction before you release your own block, therefore, merchants can reduce but not eliminate the risk by making purchasers wait some length of time that&#039;s less than a confirm.&lt;br /&gt;
&lt;br /&gt;
Because pulling off this attack is not trivial, merchants who need to sell things automatically and instantly are most likely to just price the cost of reversal fraud in, or use insurance.&lt;br /&gt;
&lt;br /&gt;
=== I was sent some bitcoins and they haven&#039;t arrived yet! Where are they? ===&lt;br /&gt;
&lt;br /&gt;
Don&#039;t panic!  There are a number of reasons why your bitcoins might not show up yet, and a number of ways to diagnose them.  &lt;br /&gt;
&lt;br /&gt;
The latest version of the Bitcoin-Qt client tells you how far it has yet to go in downloading the blockchain.  Hover over the icon in the bottom right corner of the client to learn your client&#039;s status.&lt;br /&gt;
&lt;br /&gt;
If it has not caught up then it&#039;s possible that your transaction hasn&#039;t been included in a block yet.  &lt;br /&gt;
&lt;br /&gt;
You can check pending transactions in the network by going [http://blockchain.info here] and then searching for your address.  If the transaction is listed here then it&#039;s a matter of waiting until it gets included in a block before it will show in your client.  &lt;br /&gt;
&lt;br /&gt;
If the transaction is based on a coin that was in a recent transaction then it could be considered a low priority transaction. Transfers can take longer if the transaction fee paid was not high enough.  If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.&lt;br /&gt;
&lt;br /&gt;
=== Why does my Bitcoin address keep changing? ===&lt;br /&gt;
&lt;br /&gt;
Whenever the address listed in &amp;quot;Your address&amp;quot; receives a transaction, Bitcoin replaces it with a new address. This is meant to encourage you to use a new address for every transaction, which enhances [[anonymity]]. All of your old addresses are still usable: you can see them in &#039;&#039;Settings -&amp;gt; Your Receiving Addresses&#039;&#039;.&lt;br /&gt;
&lt;br /&gt;
===How much will the transaction fee be?===&lt;br /&gt;
&lt;br /&gt;
Some transactions might require a [[transaction fee]] for them to get confirmed in a timely manner.  The transaction fee is processed by and received by the bitcoin miner.  The most recent version of the Bitcoin client will estimate an appropriate fee when a fee might be required.&lt;br /&gt;
&lt;br /&gt;
The fee is added to the payment amount.  For example, if you are sending a 1.234 BTC payment and the client requires a 0.0005 BTC fee, then 1.2345 BTC will be subtracted from the wallet balance for the entire transaction and the address for where the payment was sent will receive a payment of 1.234 BTC.&lt;br /&gt;
&lt;br /&gt;
A fee might be imposed because your transaction looks like a denial of service attack to the Bitcoin system. For example, it might be burdensome to transmit or it might recycle Bitcoins you recently received.  The wallet software attempts to avoid generating burdensome transactions, but it isn&#039;t always able to do so: The funds in your wallet might be new or composed of many tiny payments. &lt;br /&gt;
&lt;br /&gt;
Because the fee is related to the amount of data that makes up the transaction and not to the amount of Bitcoins being sent, the fee may seem extremely low (0.0005 BTC for a 1,000 BTC transfer) or unfairly high (0.004 BTC for a 0.02 BTC payment, or about 20%).  If you are receiving tiny amounts (&#039;&#039;e.g.&#039;&#039; as small payments from a mining pool) then fees when sending will be higher than if your activity follows the pattern of conventional consumer or business transactions. &lt;br /&gt;
&lt;br /&gt;
As of Bitcoin 0.5.3 the required fee will not be higher than 0.05 BTC. For most users there is usually no required fee at all. If a fee is required it will most commonly be 0.0005 BTC.&lt;br /&gt;
&lt;br /&gt;
=== What happens when someone sends me a bitcoin but my computer is powered off? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoins are not actually &amp;quot;sent&amp;quot; to your wallet; the software only uses that term so that we can use the currency without having to learn new concepts.  Your wallet is only needed when you wish to spend coins that you&#039;ve received.&lt;br /&gt;
&lt;br /&gt;
If you are sent coins when your wallet client program is not running, and you later launch the wallet client program, the coins will eventually appear as if they were just received in the wallet. That is to say, when the client program is started it must download blocks and catch up with any transactions it did not already know about.&lt;br /&gt;
&lt;br /&gt;
=== How long does &amp;quot;synchronizing&amp;quot; take when the Bitcoin client is first installed? What&#039;s it doing? ===&lt;br /&gt;
&lt;br /&gt;
The popular Bitcoin client software from bitcoin.org implements a &amp;quot;full&amp;quot; Bitcoin node: It can carry out all the duties of the Bitcoin P2P system, it isn&#039;t simply a &amp;quot;client&amp;quot;. One of the principles behind the operation of full Bitcoin nodes is that they don&#039;t assume that the other participants have followed the rules of the Bitcoin system. During synchronization, the software is processing historical Bitcoin transactions and making sure for itself that all of the rules of the system have been correctly followed.&lt;br /&gt;
&lt;br /&gt;
In normal operation, after synchronizing, the software should use a hardly noticeable amount of your computer&#039;s resources.&lt;br /&gt;
&lt;br /&gt;
When the wallet client program is first installed, its initial validation requires a lot of work from your computer&#039;s hard disk, so the amount of time to synchronize depends on your disk speed and, to a lesser extent, your CPU speed. It can take anywhere from a few hours to a day or so. On a slow computer it could take more than 40 hours of continuous synchronization, so check your computer&#039;s power-saving settings to ensure that it does not turn its hard disk off when unattended for a few hours.  You can use the Bitcoin software during synchronization, but you may not see recent payments to you until the client program has caught up to the point where those transactions happened.&lt;br /&gt;
&lt;br /&gt;
If you feel that this process takes too long, you can download a pre-synchronized blockchain from [http://eu2.bitcoincharts.com/blockchain/ http://eu2.bitcoincharts.com/blockchain/]. Alternatively, you can try an alternative &amp;quot;lite&amp;quot; client such as Multibit or a super-light client like electrum, though these clients have somewhat weaker security, are less mature, and don&#039;t contribute to the health of the P2P network.&lt;br /&gt;
&lt;br /&gt;
==Networking==&lt;br /&gt;
=== Do I need to configure my firewall to run Bitcoin? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin will connect to other nodes, usually on TCP port 8333. You will need to allow outgoing TCP connections to port 8333 if you want to allow your Bitcoin client to connect to many nodes. [[Testnet]] uses TCP port 18333 instead of 8333.&lt;br /&gt;
&lt;br /&gt;
If you want to restrict your firewall rules to a few IPs, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]].&lt;br /&gt;
&lt;br /&gt;
=== How does the peer finding mechanism work? ===&lt;br /&gt;
&lt;br /&gt;
Bitcoin finds peers primarily by forwarding peer announcements within its own network and each node saves a database of peers that it&#039;s aware of, for future use. In order to bootstrap this process Bitcoin needs a list of initial peers, these can be provided manually but normally it obtains them by querying a set of DNS domain names which have automatically updated lists, if that doesn&#039;t work it falls back to a built-in list which is updated from time to time in new versions of the software. There is also an IRC based mechanism but it is disabled by default.&lt;br /&gt;
&lt;br /&gt;
==Mining==&lt;br /&gt;
===What is mining?===&lt;br /&gt;
[[Mining]] is the process of spending computation power to secure Bitcoin transactions against reversal and introducing new Bitcoins to the system.&lt;br /&gt;
&lt;br /&gt;
Technically speaking, mining is the calculation of a [[hash]] of the a block header, which includes among other things a reference to the previous block, a hash of a set of transactions and a [[nonce]]. If the hash value is found to be less than the current [[target]] (which is inversely proportional to the [[difficulty]]), a new block is formed and the miner gets the newly generated Bitcoins (25 per block at current levels). If the hash is not less than the current target, a new nonce is tried, and a new hash is calculated. This is done millions of times per second by each miner.&lt;br /&gt;
&lt;br /&gt;
===Is mining used for some useful computation?===&lt;br /&gt;
The computations done when mining are internal to Bitcoin and not related to any other distributed computing projects. They serve the purpose of securing the Bitcoin network, which is useful.&lt;br /&gt;
&lt;br /&gt;
===Is it not a waste of energy?===&lt;br /&gt;
Spending energy on creating and securing a free monetary system is hardly a waste. Also, services necessary for the operation of currently widespread monetary systems, such as banks and credit card companies, also spend energy, arguably more than Bitcoin would.&lt;br /&gt;
&lt;br /&gt;
===Why don&#039;t we use calculations that are also useful for some other purpose?===&lt;br /&gt;
To provide security for the Bitcoin network, the calculations involved need to have some [http://bitcoin.stackexchange.com/questions/5617/why-are-bitcoin-calculation-useless/5618#5618 very specific features]. These features are incompatible with leveraging the computation for other purposes.&lt;br /&gt;
&lt;br /&gt;
===How can we stop miners from creating zero transaction blocks?===&lt;br /&gt;
The incentive for miners to include transactions is in the fees that come along with them. If we were to implement some minimum number of transactions per block it would be trivial for a miner to create and include transactions merely to surpass that threshold. As the network matures, the block reward drops, and miners become more dependent on transactions fees to pay their costs, the problem of zero transaction blocks should diminish over time.&lt;br /&gt;
&lt;br /&gt;
===How does the proof-of-work system help secure Bitcoin?===&lt;br /&gt;
To give a general idea of the mining process, imagine this setup:&lt;br /&gt;
&lt;br /&gt;
  payload = &amp;lt;some data related to things happening on the Bitcoin network&amp;gt;&lt;br /&gt;
  nonce = 1&lt;br /&gt;
  hash = [http://en.wikipedia.org/wiki/SHA2 SHA2]( [http://en.wikipedia.org/wiki/SHA2 SHA2]( payload + nonce ) )&lt;br /&gt;
&lt;br /&gt;
The work performed by a miner consists of repeatedly increasing &amp;quot;nonce&amp;quot; until&lt;br /&gt;
the hash function yields a value, that has the rare property of being below a certain&lt;br /&gt;
target threshold. (In other words: The hash &amp;quot;starts with a certain number of zeroes&amp;quot;,&lt;br /&gt;
if you display it in the fixed-length representation, that is typically used.)&lt;br /&gt;
&lt;br /&gt;
As can be seen, the mining process doesn&#039;t compute anything special. It merely&lt;br /&gt;
tries to find a number (also referred to as nonce) which - in combination with the payload -&lt;br /&gt;
results in a hash with special properties.&lt;br /&gt;
&lt;br /&gt;
The advantage of using such a mechanism consists of the fact, that it is very easy to check a result: Given the payload and a specific nonce, only a single call of the hashing function is needed to verify that the hash has the required properties. Since there is no known way to find these hashes other than brute force, this can be used as a &amp;quot;proof of work&amp;quot; that someone invested a lot of computing power to find the correct nonce for this payload.&lt;br /&gt;
&lt;br /&gt;
This feature is then used in the Bitcoin network to secure various aspects. An attacker&lt;br /&gt;
that wants to introduce malicious payload data into the network, will need to do the&lt;br /&gt;
required proof of work before it will be accepted. And as long as honest miners have more&lt;br /&gt;
computing power, they can always outpace an attacker.&lt;br /&gt;
&lt;br /&gt;
Also see [http://en.wikipedia.org/wiki/Hashcash Hashcash] and [http://en.wikipedia.org/wiki/Proof-of-work_system Proof-of-work system] and [http://en.wikipedia.org/wiki/SHA2 SHA2] and on Wikipedia.&lt;br /&gt;
&lt;br /&gt;
===Why was the &amp;quot;Generate coin&amp;quot; option of the client software removed?===&lt;br /&gt;
&lt;br /&gt;
In the early days of Bitcoin, it was easy for anyone to find new blocks using standard CPUs. As more and more people started mining, the [[difficulty]] of finding new blocks has greatly increased to the point where the average time for a CPU to find a single block can be many years. The only cost-effective method of [[Mining|mining]] is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]) and/or joining a [[Bitcoin Pool|mining pool]]. Since solo CPU mining is essentially useless, it was removed from the GUI of the Bitcoin software.&lt;br /&gt;
&lt;br /&gt;
==Security==&lt;br /&gt;
&lt;br /&gt;
===Could miners collude to give themselves money or to fundamentally change the nature of Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
There are two questions in here.  Let&#039;s look at them separately.&lt;br /&gt;
&lt;br /&gt;
;Could miners gang up and give themselves money?&lt;br /&gt;
&lt;br /&gt;
Mining itself is the process of creating new blocks in the block chain.  Each block contains a list of all the transactions that have taken place across the entire Bitcoin network since the last block was created, as well as a hash of the previous block.  New blocks are &#039;mined&#039;, or rather, generated, by  Bitcoin clients correctly guessing sequences of characters in codes called &#039;hashes,&#039; which are created using information from previous blocks.  Bitcoin users may download specialized &#039;mining&#039; software, which  allows them to dedicate some amount of their processing power – however large or small – to guessing at strings within the hash of the previous block.  Whoever makes the right guess first, thus creating a new block, receives a reward in Bitcoins.&lt;br /&gt;
	&lt;br /&gt;
The block chain is one of the two structures that makes Bitcoin secure, the other being the public-key encryption system on which Bitcoin trade is based.  The block chain assures that not only is every single transaction that ever takes place recorded, but that every single transaction is recorded on the computer of anyone who chooses to store the relevant information.  Many, many users have complete records of every transaction in Bitcoins history readily available to them at any point, and anyone who wants in the information can obtain it with ease.  These things make Bitcoin very hard to fool.&lt;br /&gt;
&lt;br /&gt;
The Bitcoin network takes considerable processing power to run, and since those with the most processing power can make the most guesses, those who put the most power toward to sustaining the network earn the most currency.  Each correct guess yields, at present, twenty-five Bitcoins, and as Bitcoins are presently worth something (although the value still fluctuates) every miner who earns any number of Bitcoins makes money.  Some miners pull in Bitcoins on their own; and some also join or form pools wherein all who contribute earn a share of the profits.  &lt;br /&gt;
	&lt;br /&gt;
Therefore, first answer is a vehement “yes”  – not only can miners collude to get more money, Bitcoin is designed to encourage them to do so.  Bitcoin pools are communal affairs, and there is nothing dishonest or underhanded about them.&lt;br /&gt;
&lt;br /&gt;
Of course, the real question is:&lt;br /&gt;
&lt;br /&gt;
;Can they do so in ways not sanctioned by Bitcoin developers?  Is there any way to rip off the network and make loads of money dishonestly?&lt;br /&gt;
&lt;br /&gt;
Bitcoin isn&#039;t infallible.  It can be cheated, but doing so is extremely difficult.  Bitcoin was designed to evade some of the central problems with modern currencies – namely, that their trustworthiness hinges upon that of people who might not have users&#039; best interests in mind.  Every currency in the world (other than Bitcoin) is controlled by large institutions who keep track of what&#039;s done with it, and who can manipulate its value.  And every other currency has value because people trust the institutions that control them.&lt;br /&gt;
&lt;br /&gt;
Bitcoin doesn&#039;t ask that its users trust any institution.  Its security is based on the cryptography that is an integral part of its structure, and that is readily available for any and all to see.  Instead of one entity keeping track of transactions, the entire network does, so Bitcoins are astoundingly difficult to steal, or double-spend. Bitcoins are created in a regular and predictable fashion, and by many different users, so no one can decide to make a whole lot more and lessen their value.  In short, Bitcoin is designed to be inflation-proof, double-spend-proof and completely distributed.&lt;br /&gt;
&lt;br /&gt;
Nonetheless, there are a few ways that one can acquire Bitcoins dishonestly.  Firstly, one can steal private keys.  Key theft isn&#039;t something that Bitcoin security has been designed to prevent: it&#039;s up to users to keep theirs safe.  But the cryptography is designed so that it is completely impossible to deduce someone&#039;s private key from their public one. As long as you keep your private key to yourself, you don&#039;t have much to worry about.  Furthermore, one could theoretically create a new block chain, but due to the way in which the block chain is constructed, this would be extremely difficult and require massive amounts of processing power.  A full explanation of the difficulties involved can be found in the [[block chain]] article.&lt;br /&gt;
&lt;br /&gt;
Bitcoin can be ripped off – but doing so would be extremely hard and require considerable expertise and a staggering amount of processing power.  And it&#039;s only going to get harder with time.  Bitcoin isn&#039;t impenetrable, but it&#039;s close enough to put any real worries in the peripherals.&lt;br /&gt;
	&lt;br /&gt;
;Could miners fundamentally change the nature of Bitcoin?&lt;br /&gt;
&lt;br /&gt;
Once again, almost certainly not.&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a distributed network, so any changes implemented to the system must be accepted by all users.  Someone trying to change the way Bitcoins are generated would have to convince every user to download and use their software – so the only changes that would go through are those that would be equally benefit all users. &lt;br /&gt;
&lt;br /&gt;
And thus, it is more or less impossible for anyone to change the function of Bitcoin to their advantage.  If users don&#039;t like the changes, they won&#039;t adopt them, whereas if users do like them, then these will help everyone equally.  Of course, one can conceive of a situation where someone manages to get a change pushed through that provides them with an advantage that no one notices, but given that Bitcoin is structurally relatively simple, it is unlikely that any major changes will go through without someone noticing first.&lt;br /&gt;
&lt;br /&gt;
The fact that such changes are so difficult to make testifies to the fully distributed nature of Bitcoin.  Any centrally controlled currency can be modified by its central agency without the consent of its adherents.  Bitcoin has no central authority, so it changes only at the behest of the whole community.  Bitcoins development represents a kind of collective evolution; the first of its kind among currencies.&lt;br /&gt;
&lt;br /&gt;
==Help==&lt;br /&gt;
===I&#039;d like to learn more.  Where can I get help?===&lt;br /&gt;
&lt;br /&gt;
* Read the [[Introduction|introduction to bitcoin]] &lt;br /&gt;
* See the videos, podcasts, and blog posts from the [[Press]]&lt;br /&gt;
* Read and post on the [[:Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]&lt;br /&gt;
* Chat on one of the [[:Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels&lt;br /&gt;
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works&lt;br /&gt;
* Ask questions on the [http://bitcoin.stackexchange.com Bitcoin Stack Exchange]&lt;br /&gt;
&lt;br /&gt;
==See Also==&lt;br /&gt;
&lt;br /&gt;
* [[Man page]]&lt;br /&gt;
* [[Introduction]]&lt;br /&gt;
&lt;br /&gt;
[[de:FAQ]]&lt;br /&gt;
[[zh-cn:FAQ]]&lt;br /&gt;
[[fr:FAQ]]&lt;br /&gt;
[[ru:FAQ]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Technical]]&lt;br /&gt;
[[Category:Vocabulary]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Introducere&amp;diff=74</id>
		<title>Introducere</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Introducere&amp;diff=74"/>
		<updated>2013-05-24T07:32:43Z</updated>

		<summary type="html">&lt;p&gt;8fold: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Scopul acestei pagini este să ofere o imagine de ansamblu asupra economiei și sistemului Bitcoin.&lt;br /&gt;
&lt;br /&gt;
==Concepte de baza==&lt;br /&gt;
&lt;br /&gt;
===Moneda===&lt;br /&gt;
&lt;br /&gt;
Alice wants to buy the [http://www.grasshillalpacas.com/alpacaproductsforbitcoinoffer.html Alpaca socks] which Bob has for sale. In return, she must provide something of equal value to Bob. The most efficient way to do this is by using a medium of exchange that Bob accepts which would be classified as currency. Currency makes trade easier by eliminating the need for [http://en.wikipedia.org/wiki/Coincidence_of_wants coincidence of wants] required in other systems of trade such as barter. Currency adoption and acceptance can be global, national, or in some cases local or community-based.&lt;br /&gt;
&lt;br /&gt;
===Banci===&lt;br /&gt;
&lt;br /&gt;
Alice need not provide currency to Bob in-person. She may instead transfer this value by first entrusting her currency to a bank who promises to store and protect Alice&#039;s currency notes. The bank gives Alice a written promise (called a &amp;quot;bank statement&amp;quot;) that entitles her to withdraw the same number of currency bills that she deposited. Since the money is still Alice&#039;s, she is entitled to do with it whatever she pleases, and the bank (like most banks), for a small fee, will do Alice the service of passing on the currency bills to Bob on her behalf. This is done by Alice&#039;s bank by giving the dollar bills to Bob&#039;s bank and informing them that the money is for Bob, who will then see the amount the next time he checks his balance or receives his bank statement.&lt;br /&gt;
&lt;br /&gt;
Since banks have many customers, and bank employees require money for doing the job of talking to people and signing documents, banks in recent times have been using machines such as ATMs and web servers that do the job of interacting with customers instead of paid bank employees. The task of these machines is to learn what each customer wants to do with their money and, to the extent that it is possible, act on what the customer wants (for example, ATMs can hand out cash). Customers can always know how much money they have in their accounts, and they are confident that the numbers they see in their bank statements and on their computer screens accurately reflect the number of dollars that they can get from the bank on demand. They can be so sure of this that they can accept those numbers in the same way they accept paper banknotes (this is similar to the way people started accepting paper dollars when they had been accepting gold or silver).&lt;br /&gt;
&lt;br /&gt;
Such a system has several disadvantages:&lt;br /&gt;
* It is costly. [https://en.wikipedia.org/wiki/Electronic_funds_transfer EFTs] in Europe can cost 25 euros. Credit transactions can cost several percent of the transaction.&lt;br /&gt;
* It is slow. Checking and low cost wire services take days to complete.&lt;br /&gt;
* In most cases, it cannot be anonymous.&lt;br /&gt;
* Accounts can be frozen, or their balance partially or wholly confiscated.&lt;br /&gt;
* Banks and other payment processors like PayPal, Visa, and Mastercard may refuse to process payments for certain legal entities. &lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
Bitcoin is a system of owning and voluntarily transferring amounts of so-called &#039;&#039;bitcoins&#039;&#039;, in a manner similar to an on-line banking, but pseudonymously and without reliance on a central authority to maintain account balances. If bitcoins are valuable, it is because they are useful and limited in supply.&lt;br /&gt;
&lt;br /&gt;
==Despre Bitcoin==&lt;br /&gt;
&lt;br /&gt;
===Crearea monezilor===&lt;br /&gt;
The creation of coins must be limited for the currency to have any value. &lt;br /&gt;
&lt;br /&gt;
New coins are slowly [[Mining|mined]] into existence by following a mutually agreed-upon set of rules. A user [[Mining|mining]] bitcoins is running a software program that searches tirelessly for a solution to a very difficult math problem whose difficulty is precisely known. The difficulty is automatically adjusted regularly so that the number of solutions found globally, by everyone, for a given unit of time is constant: an average of 6 per hour. When a solution is found, the user may tell everyone of the existence of this newly found solution, along with other information, packaged together in what is called a &amp;quot;[[Block|block]]&amp;quot;. &lt;br /&gt;
&lt;br /&gt;
Blocks create 25 new bitcoins at present. This amount, known as the block reward, is an incentive for people to perform the computation work required for generating blocks. Roughly every 4 years, the number of bitcoins that can be &amp;quot;mined&amp;quot; in a block reduces by 50%. Originally the block reward was 50 bitcoins; it halved in November 2012.  Any block that is created by a malicious user that does not follow this rule (or any other rules) will be rejected by everyone else. In the end, no more than 21 million bitcoins will ever exist. &lt;br /&gt;
&lt;br /&gt;
Because the block reward will decrease over the long term, miners will some day instead pay for their hardware and electricity costs by collecting [[Transaction_fee|transaction fees]]. The sender of money may voluntarily pay a small transaction fee which will be kept by whoever finds the next block. Paying this fee will encourage miners to include the transaction in a block more quickly.&lt;br /&gt;
&lt;br /&gt;
===Efectuarea platilor===&lt;br /&gt;
To guarantee that a third-party, let&#039;s call her Eve, cannot spend other people&#039;s bitcoins by creating transactions in their names, Bitcoin uses [[Wikipedia:Public-key_cryptography|public key cryptography]] to make and verify digital signatures. In this system, each person, such as Alice or Bob, has one or more addresses each with an associated pair of public and private keys that they may hold in a [[Wallet|wallet]]. Only the user with the private key can sign a transaction to give some of their bitcoins to somebody else, but anyone can validate the signature using that user’s public key.&lt;br /&gt;
&lt;br /&gt;
Suppose Alice wants to send a bitcoin to Bob.&lt;br /&gt;
* Bob sends his address (from which the public key can be derived) to Alice.&lt;br /&gt;
* Alice adds Bob’s public key and the amount of bitcoins to transfer to a message: a &#039;transaction&#039; message.&lt;br /&gt;
* Alice signs the transaction with her private key.&lt;br /&gt;
* Alice broadcasts the transaction on the Bitcoin network for all to see.&lt;br /&gt;
&lt;br /&gt;
(Only the first two steps require human action. The rest is done by the Bitcoin client software.)&lt;br /&gt;
&lt;br /&gt;
Looking at this transaction from the outside, anyone who knows that these addresses belong to Alice and Bob can see that Alice has agreed to transfer the amount to Bob, because nobody else has Alice&#039;s private key. Alice would be foolish to give her private key to other people, as this would allow them to sign transactions in her name, removing funds from her control.&lt;br /&gt;
&lt;br /&gt;
Later on, when Bob wishes to transfer the same bitcoins to Charley, he will do the same thing:&lt;br /&gt;
* Charlie sends Bob his address.&lt;br /&gt;
* Bob adds Charlie&#039;s public key and the amount of bitcoins to transfer to a message: a &#039;transaction&#039; message.&lt;br /&gt;
* Bob signs the transaction with his private key.&lt;br /&gt;
* Bob broadcasts the transaction on the Bitcoin network for all to see. &lt;br /&gt;
&lt;br /&gt;
Only Bob can do this because only he has the private key that can create a valid signature for the transaction.&lt;br /&gt;
&lt;br /&gt;
Eve cannot change whose coins these are by replacing Bob’s public key with her public key, because Alice signed the transfer to Bob using her own private key, which is kept secret from Eve, and instructing that the coins which were hers now belong to Bob. So if Charlie accepts that the original coin was in the hands of Alice, he will also accept the fact that this coin was later passed to Bob, and now Bob is passing this same coin to him.&lt;br /&gt;
&lt;br /&gt;
===Cum se previne [[cheltuirea dubla]](double-spending)===&lt;br /&gt;
The process described above does not prevent Alice from using the same bitcoins in more than one transaction. The following process does; this is the primary innovation behind Bitcoin.&lt;br /&gt;
&lt;br /&gt;
* Details about the [[Transactions|transaction]] are [[Network|sent and forwarded]] to all or as many other computers as possible.&lt;br /&gt;
* A constantly growing chain of [[Blocks|blocks]] that contains a record of all transactions is collectively maintained by all computers (each has a full copy).&lt;br /&gt;
* To be accepted in the chain, transaction blocks must be valid and must include [[proof of work]] (one block generated by the network every 10 minutes).&lt;br /&gt;
* Blocks are chained in a way so that, if any one is modified, all following blocks will have to be recomputed.&lt;br /&gt;
* When multiple valid continuations to this chain appear, only the longest such branch is accepted and it is then extended further.&lt;br /&gt;
&lt;br /&gt;
When Bob sees that his transaction has been included in a block, which has been made part of the single longest and fastest-growing block chain (extended with significant computational effort), he can be confident that the transaction by Alice has been accepted by the computers in the network and is permanently recorded, preventing Alice from creating a second transaction with the same coin. In order for Alice to thwart this system and double-spend her coins, she would need to muster more computing power than all other Bitcoin users combined.&lt;br /&gt;
&lt;br /&gt;
===Anonimitate===&lt;br /&gt;
When it comes to the Bitcoin network itself, there are no &amp;quot;accounts&amp;quot; to set up, and no e-mail addresses, user-names or passwords are required to hold or spend bitcoins. Each balance is simply associated with an address and its public-private key pair. The money &amp;quot;belongs&amp;quot; to anyone who has the private key and can sign transactions with it. Moreover, those keys do not have to be registered anywhere in advance, as they are only used when required for a transaction. Transacting parties do not need to know each other&#039;s identity in the same way that a store owner does not know a cash-paying customer&#039;s name.&lt;br /&gt;
&lt;br /&gt;
A [[Address|Bitcoin address]] mathematically corresponds to a public key and looks like this:&lt;br /&gt;
&lt;br /&gt;
:1PC9aZC4hNX2rmmrt7uHTfYAS3hRbph4UN&lt;br /&gt;
&lt;br /&gt;
Each person can have many such addresses, each with its own balance, which makes it very difficult to know which person owns what amount. In order to protect his [[Anonymity|privacy]], Bob can generate a new public-private key pair for each individual receiving transaction and the Bitcoin software encourages this behavior by default. Continuing the example from above, when Charlie receives the bitcoins from Bob, Charlie will not be able to identify who owned the bitcoins before Bob.&lt;br /&gt;
&lt;br /&gt;
===Capitalizare/ Nomenclatura===&lt;br /&gt;
Since Bitcoin is both a currency and a protocol, capitalization can be confusing. Accepted practice is to use &#039;&#039;Bitcoin&#039;&#039; (singular with an upper case letter B) to label the protocol, software, and community, and &#039;&#039;bitcoins&#039;&#039; (with a lower case b) to label units of the currency.&lt;br /&gt;
&lt;br /&gt;
==Unde se poate vedea si explora==&lt;br /&gt;
You can directly explore the system in action by visiting [http://blockchain.info/ Blockchain.info] or [http://blockexplorer.com/ Bitcoin Block Explorer].&lt;br /&gt;
The site shows you the latest blocks in the block chain. The [[Block_chain|block chain]] contains the agreed history of all transactions that took place in the system.&lt;br /&gt;
Note how many blocks were generated in the last hour, which on average will be 6. Also notice the number of transactions and the total amount transferred in the last hour (last time I checked it was about 64 and 15K).&lt;br /&gt;
This should give you an indication of how active the system is.&lt;br /&gt;
&lt;br /&gt;
Next, navigate to one of these blocks.&lt;br /&gt;
The block&#039;s [[hash]] begins with a run of zeros. This is what made creating the block so difficult; a hash that begins with many zeros is much more difficult to find than a hash with few or no zeros. The computer that generated this block had to try many &#039;&#039;Nonce&#039;&#039; values (also listed on the block&#039;s page) until it found one that generated this run of zeros.&lt;br /&gt;
Next, see the line titled &#039;&#039;Previous block&#039;&#039;. Each block contains the hash of the block that came before it. This is what forms the chain of blocks.&lt;br /&gt;
Now take a look at all the transactions the block contains. The first transaction is the income earned by the computer that generated this block. It includes a fixed amount of coins created out of &amp;quot;thin air&amp;quot; and possibly a fee collected from other transactions in the same block.&lt;br /&gt;
&lt;br /&gt;
Drill down into any of the transactions and you will see how it is made up of one or more amounts coming in and out.&lt;br /&gt;
Having more than one incoming and outgoing amount in a transaction enables the system to join and break amounts in any possible way, allowing for any fractional amount needed. Each incoming amount is a past transaction (which you can also view) from someone&#039;s address, and each outgoing amount is addressed to someone and will be part of a future transaction (which you can also navigate down into if it has already taken place.)&lt;br /&gt;
&lt;br /&gt;
Finally you can follow any of the [[Address|addresses]] links and see what public information is available for them.&lt;br /&gt;
&lt;br /&gt;
To get an impression of the amount of activity on the Bitcoin network, you might like to visit the monitoring websites [[Bitcoin Monitor]] and [[Bitcoin Watch]]. The first shows a real-time visualization of events on the Bitcoin network, and the second lists general statistics on the amount and size of recent transactions.&lt;br /&gt;
&lt;br /&gt;
===Cate persoane folosesc Bitcoin?===&lt;br /&gt;
&lt;br /&gt;
This is quite a difficult question to answer accurately. One approach is to count how many bitcoin clients connected to the network in the last 24 hours. We can do this because some clients transmit their addresses to the other members of the network periodically. In September 2011 this method suggested that there were about {{formatnum:60000}} users.&lt;br /&gt;
&lt;br /&gt;
==Alte link-uri==&lt;br /&gt;
&lt;br /&gt;
* [http://www.youtube.com/watch?v=Um63OQz3bjo What is Bitcoin?] video introduction&lt;br /&gt;
* Installing Bitcoin [[getting started]] &lt;br /&gt;
* [[Using Bitcoin]]&lt;br /&gt;
* A gentle introduction to Bitcoin - [[BitcoinMe]]&lt;br /&gt;
* [http://coinlab.com/2011/12/bitcoin-primer Bitcoin Primer] from CoinLab&lt;br /&gt;
* Another introduction, &#039;&#039;The Rebooting Of Money&#039;&#039; podcast is found at [[Bitcoin Money]]&lt;br /&gt;
* A beginner&#039;s step-by-step guide to using Bitcoin, use of alternative wallets, and generally keeping your money and computer secure - [http://BitcoinIntro.com BitcoinIntro.com]&lt;br /&gt;
* [http://howtobitcoin.info howtobitcoin.info] Directory of bitcoin links for beginners&lt;br /&gt;
* Amazon Kindle Book [http://www.amazon.com/Bitcoin-Step-by-ebook/dp/B00A1CUQQU Bitcoin Step by Step] $3.99 (USD).  The author walks you step by step through getting started.&lt;br /&gt;
&lt;br /&gt;
[[zh-cn:简介]]&lt;br /&gt;
&lt;br /&gt;
[[de:Einführung]]&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Format:MainPage_Articole&amp;diff=73</id>
		<title>Format:MainPage Articole</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Format:MainPage_Articole&amp;diff=73"/>
		<updated>2013-05-24T07:31:30Z</updated>

		<summary type="html">&lt;p&gt;8fold: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--&lt;br /&gt;
Primul tabel este pentru tutoriale. Coloana stanga = pagini scrise pentru utilizatori. Coloana dreapta = pagini pentru developers.&lt;br /&gt;
Al doilea tabel este pentru categorii.&lt;br /&gt;
--&amp;gt;&lt;br /&gt;
&lt;br /&gt;
{|cellpadding=&amp;quot;2&amp;quot; style=&amp;quot;background-color: inherit;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
* [[Introducere]]&lt;br /&gt;
* [http://www.weusecoins.com/getting-started.php Primii pași]&lt;br /&gt;
* [[Mituri]]&lt;br /&gt;
* [[Securizarea portofelului]]&lt;br /&gt;
* [[Comparatie hardware minat]]&lt;br /&gt;
| scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
* [[PHP developer intro]]&lt;br /&gt;
* [[Despre API (JSON-RPC)]]&lt;br /&gt;
* [[Specificatiile Protocolului]]&lt;br /&gt;
* [[Tranzactionare Securizata|Cele mai bune practici pentru traderi]]&lt;br /&gt;
* [[Propuneri pentru îmbunătățirea Bitcoin]]&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{|cellpadding=&amp;quot;2&amp;quot; style=&amp;quot;background-color: inherit;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
|-&lt;br /&gt;
|&lt;br /&gt;
* [[Software]]&lt;br /&gt;
* [[Minerit]]&lt;br /&gt;
* [[:Category:Exchanges|Case de schimb]]&lt;br /&gt;
* [[:Category:Directories|Local Directories]]&lt;br /&gt;
* [[:Category:Marketing|Marketing resources]]&lt;br /&gt;
* [[People]]&lt;br /&gt;
|&lt;br /&gt;
* [[:Category:Technical|Articole tehnice]]&lt;br /&gt;
* [[:Category:Clients|Clients]] / [[:Category:Frontends|Frontends]]&lt;br /&gt;
* [[:Category:Economics|Economie]]&lt;br /&gt;
* [[Trade|Afaceri (Schimb)]]&lt;br /&gt;
* [[:Category:Games|Jocuri]]&lt;br /&gt;
* [[Real world shops|Real world merchants map]]&lt;br /&gt;
* [[Intalniri]]&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;div style=&amp;quot;text-align: right;&amp;quot; class=&amp;quot;noprint&amp;quot;&amp;gt;&amp;lt;span class=&amp;quot;plainlinks&amp;quot;&amp;gt;[{{fullurl:Template:MainPage_Articole|action=edit}} &#039;&#039;&#039;Editeaza&#039;&#039;&#039;]&amp;lt;/span&amp;gt; &amp;amp;ndash; &#039;&#039;&#039;[[Special:Categories|Vezi mai mult]]&#039;&#039;&#039;&amp;lt;/div&amp;gt;&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Format:MainPage_Articole&amp;diff=72</id>
		<title>Format:MainPage Articole</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Format:MainPage_Articole&amp;diff=72"/>
		<updated>2013-05-24T07:29:38Z</updated>

		<summary type="html">&lt;p&gt;8fold: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--&lt;br /&gt;
Primul tabel este pentru tutoriale. Coloana stanga = pagini scrise pentru utilizatori. Coloana dreapta = pagini pentru developers.&lt;br /&gt;
Al doilea tabel este pentru categorii.&lt;br /&gt;
--&amp;gt;&lt;br /&gt;
&lt;br /&gt;
{|cellpadding=&amp;quot;2&amp;quot; style=&amp;quot;background-color: inherit;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
* [[Introducere]]&lt;br /&gt;
* [http://www.weusecoins.com/getting-started.php Primii pași]&lt;br /&gt;
* [[Mituri]]&lt;br /&gt;
* [[Securizarea portofelului]]&lt;br /&gt;
* [[Comparatie hardware minat]]&lt;br /&gt;
| scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
* [[PHP developer intro]]&lt;br /&gt;
* [[Despre API (JSON-RPC)]]&lt;br /&gt;
* [[Specificatiile Protocolului]]&lt;br /&gt;
* [[Tranzactionare Securizata|Cele mai bune practici pentru traderi]]&lt;br /&gt;
* [[Propuneri pentru imbunatirea Bitcoin]]&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{|cellpadding=&amp;quot;2&amp;quot; style=&amp;quot;background-color: inherit;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
|-&lt;br /&gt;
|&lt;br /&gt;
* [[Software]]&lt;br /&gt;
* [[Minerit]]&lt;br /&gt;
* [[:Category:Exchanges|Case de schimb]]&lt;br /&gt;
* [[:Category:Directories|Local Directories]]&lt;br /&gt;
* [[:Category:Marketing|Marketing resources]]&lt;br /&gt;
* [[People]]&lt;br /&gt;
|&lt;br /&gt;
* [[:Category:Technical|Articole tehnice]]&lt;br /&gt;
* [[:Category:Clients|Clients]] / [[:Category:Frontends|Frontends]]&lt;br /&gt;
* [[:Category:Economics|Economie]]&lt;br /&gt;
* [[Trade|Afaceri (Schimb)]]&lt;br /&gt;
* [[:Category:Games|Jocuri]]&lt;br /&gt;
* [[Real world shops|Real world merchants map]]&lt;br /&gt;
* [[Intalniri]]&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;div style=&amp;quot;text-align: right;&amp;quot; class=&amp;quot;noprint&amp;quot;&amp;gt;&amp;lt;span class=&amp;quot;plainlinks&amp;quot;&amp;gt;[{{fullurl:Template:MainPage_Articole|action=edit}} &#039;&#039;&#039;Editeaza&#039;&#039;&#039;]&amp;lt;/span&amp;gt; &amp;amp;ndash; &#039;&#039;&#039;[[Special:Categories|Vezi mai mult]]&#039;&#039;&#039;&amp;lt;/div&amp;gt;&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
	<entry>
		<id>https://ro.bitcoin.it/w/index.php?title=Format:MainPage_Articole&amp;diff=71</id>
		<title>Format:MainPage Articole</title>
		<link rel="alternate" type="text/html" href="https://ro.bitcoin.it/w/index.php?title=Format:MainPage_Articole&amp;diff=71"/>
		<updated>2013-05-24T07:16:54Z</updated>

		<summary type="html">&lt;p&gt;8fold: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--&lt;br /&gt;
Primul tabel este pentru tutoriale. Coloana stanga = pagini scrise pentru utilizatori. Coloana dreapta = pagini pentru developers.&lt;br /&gt;
Al doilea tabel este pentru categorii.&lt;br /&gt;
--&amp;gt;&lt;br /&gt;
&lt;br /&gt;
{|cellpadding=&amp;quot;2&amp;quot; style=&amp;quot;background-color: inherit;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
* [[Introducere]]&lt;br /&gt;
* [http://www.weusecoins.com/getting-started.php Primii pași]&lt;br /&gt;
* [[Mituri]]&lt;br /&gt;
* [[Securizarea portofelului]]&lt;br /&gt;
* [[Comparatie hardware minat]]&lt;br /&gt;
| scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
* [[PHP developer intro]]&lt;br /&gt;
* [[Despre API (JSON-RPC)]]&lt;br /&gt;
* [[Specificatiile Protocolului]]&lt;br /&gt;
* [[Tranzactionare Securizata|Cele mai bune practici pentru traderi]]&lt;br /&gt;
* [[Propuneri pentru imbunatirea Bitcoin]]&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{|cellpadding=&amp;quot;2&amp;quot; style=&amp;quot;background-color: inherit;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
! scope=&amp;quot;col&amp;quot; style=&amp;quot;width: 200px;&amp;quot; |&lt;br /&gt;
|-&lt;br /&gt;
|&lt;br /&gt;
* [[Software]]&lt;br /&gt;
* [[Mining]]&lt;br /&gt;
* [[:Category:Exchanges|Exchanges]]&lt;br /&gt;
* [[:Category:Directories|Local Directories]]&lt;br /&gt;
* [[:Category:Marketing|Marketing resources]]&lt;br /&gt;
* [[People]]&lt;br /&gt;
|&lt;br /&gt;
* [[:Category:Technical|Technical articles]]&lt;br /&gt;
* [[:Category:Clients|Clients]] / [[:Category:Frontends|Frontends]]&lt;br /&gt;
* [[:Category:Economics|Economics]]&lt;br /&gt;
* [[Trade|Businesses (Trade)]]&lt;br /&gt;
* [[:Category:Games|Jocuri]]&lt;br /&gt;
* [[Real world shops|Real world merchants map]]&lt;br /&gt;
* [[Intalniri]]&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&amp;lt;div style=&amp;quot;text-align: right;&amp;quot; class=&amp;quot;noprint&amp;quot;&amp;gt;&amp;lt;span class=&amp;quot;plainlinks&amp;quot;&amp;gt;[{{fullurl:Template:MainPage_Articole|action=edit}} &#039;&#039;&#039;Editeaza&#039;&#039;&#039;]&amp;lt;/span&amp;gt; &amp;amp;ndash; &#039;&#039;&#039;[[Special:Categories|Vezi mai mult]]&#039;&#039;&#039;&amp;lt;/div&amp;gt;&lt;/div&gt;</summary>
		<author><name>8fold</name></author>
	</entry>
</feed>