Bitcoin Wiki - User contributions [en]

Bitcoin symbol

2012-09-27T12:29:34Z

Garyrowe: Adding reference to Broad logo

== Currency code ==
The [https://secure.wikimedia.org/wikipedia/en/wiki/ISO_4217 currency code] for Bitcoin is '''BTC'''. However, at the moment it is an [https://secure.wikimedia.org/wikipedia/en/wiki/ISO_4217#Without_currency_code unofficial code] according to the ISO 4217 standard but the official code according to the Bitcoin community.

A [https://bitcointalk.org/index.php?topic=7205.msg112577 request] has been made at the [http://www.six-group.com/ organization] maintaining the currency codes in the ISO 4217 standard to support BTC. This has been declined mainly on bases that organizations such as [https://secure.wikimedia.org/wikipedia/en/wiki/Reuters Reuters] and [https://secure.wikimedia.org/wikipedia/en/wiki/Bloomberg Bloomberg] are not reporting on the Bitcoin currency. when this changes a request can be resubmitted.

== Currency sign ==

B⃦ has been the standard currency sign for BTC for a long time. Some existing Unicode symbols have been proposed but also serious work is being done on creating a custom Bitcoin sign with its own official [https://secure.wikimedia.org/wikipedia/en/wiki/Unicode Unicode] that is recognized by the [https://secure.wikimedia.org/wikipedia/en/wiki/Unicode_Consortium Unicode Consortium]. Note that a currency sign is more complex than creating a logo as will be explained below.

[[File:Example-unicode-reference-currency-signs.png|256px|thumb|right|Examples of Unicode currency sign reference glyphs]]

=== New Unicode symbol ===

In some discussions [https://bitcointalk.org/index.php?topic=41.0 41], [https://bitcointalk.org/index.php?topic=369.0 369] and [https://bitcointalk.org/index.php?topic=7215.0 7215] on the bitcoin forum several designs of an official Bitcoin sign have been proposed. This section on the Wiki is intended to streamline the process of arriving at an official Bitcoin currency sign with its own Unicode character code.

==== Goal ====
Having a unique Bitcoin currency sign will allow typographers to add their currency sign design in their fonts. This is similar as implementing support for the euro sign. Each font has its own version of the euro sign that fits with the style observed in the characters in the rest of the fonts of their typefaces. Note that the Unicode Consortium does not endorse Bitcoin in any way by assigning a Unicode character code, however, having a Unicode for the Bitcoin sign will also be good for PR and help having Bitcoin be taken more seriously.

==== Requirements and criteria ====

A reference Bitcoin sign could/should/must be:
* recognizable as a [https://secure.wikimedia.org/wikipedia/en/wiki/Currency_sign currency sign] such as $ € ¥ £ ¢ (e.g. with one or two vertical or horzontal bars)
* not confusing with existing currency sign such as Thai Baht ฿
* build from recognizable existing characters found on most [https://secure.wikimedia.org/wikipedia/en/wiki/Keyboard_layout#United_States QWERTY keyboards] such as bar |, minus -, hash # and/or capital B referring to currencies and '''B'''itcoin
* easy to use in handwriting
* easy to compose with one or more [https://help.ubuntu.com/community/GtkComposeTable#The%20Gtk%20Compose%20Table compose seuquences] that are still free and refer to the elements recognizable in the sign (For example the euro sign can be composed from = and C even though the = and C are not part of how it is pronounced.)
* ''possible'' to implement in [https://secure.wikimedia.org/wikipedia/en/wiki/Serif serif and sans-serif] (Most of the [http://www.unicode.org/charts/PDF/U20A0.pdf Unicode reference implementations] are made with serifs but sans-serif also exist in sans-serif fonts. So a reference implementation in serif to what is found in the PDF is preferred.)
* ''possible'' to implement in regular, italic, bold and bold italic (for sans-serif the italic will simply be a slanted version)
* in [https://secure.wikimedia.org/wikipedia/en/wiki/SVG SVG] and use this [http://pastebin.com/raw.php?i=FVY8W1W3 template] (save as bitcoin-sign-20110719-template.svg) with updated metadata and public domain or similar free/open/libre license

Note that a reference Bitcoin sign will only be used as a reference by the Unicode Consortium and it is up to typographers to implement their version matching the style of their typefaces and fonts.

==== Submissions====

It is possible to submit proposals for a '''reference implementation''' below until (community must determine date). They will be judged by (community must form committee for this). If you have problems submitting your design, ask a friend with knowledge on editing wikipedia for help.

{| class="wikitable sortable"
|-
! Preview !! Handwritten !! Associations !! Compose sequence(s) !! Designer !! Link to SVG file !! Notes
|-
| [[File:Bitcoin-proposal-1.png|128px]]
|| [[File:Hashbtc.jpg|128px]]
|| hash (#), numeral three (3)
|| B#, #B, 3#, #3
|| Wareen
|| [http://pastebin.com/raw.php?i=MRfcm0Cn Bitcoin-proposal-1.svg]
|| proposal based on original design idea from [https://bitcointalk.org/index.php?topic=41.msg348274#msg348274 RylandAlmanza] and [https://bitcointalk.org/index.php?topic=25102.msg325489#msg325489 netrin]
|-
| [[File:Bitcoin-sign-20110719.png|128px]]
|| [[file:Img075.jpg|128px]]
|| double barred dollar sign ($), capital b (B)
|| B|, |B, B=, =B
|| Pander
|| [http://pastebin.com/raw.php?i=XYsc9DeS bitcoin-sign-20110719.svg]
|| example submission based on [[File:F33980a445.png]]
|}

=== Existing Unicode symbol ===

There is a discussion over [https://bitcointalk.org/index.php?topic=369.0 which Unicode symbol might be the best suited] for bitcoin.

To type Unicode characters, refer to:

* [[Microsoft Windows Unicode Input]]
* [[How to easily type the circled B symbol on a Mac]]

It has led to the following options:

{| class="wikitable sortable"
|-
! Proposed character !! Description & Pros & Cons !! Unicode name !! Unicode decimal input !! Unicode hex input
|-
| ฿ ||
* Pros: Gives a currency-like look (it is the symbol for an existing currency, the Thai Baht, but other currency symbols often get reused, like the $); displayed correctly on all known OSes
* Cons: It is already used for the Thai currency, and might confuse people
|| THAI CURRENCY SYMBOL BAHT || || Alt +0E3F
|-
| Ⓑ ||
*Pros: Similar to current bitcoin.org logo
|| CIRCLED LATIN CAPITAL LETTER B || || Alt +24B7
|-
| B⃫ ||
|| LATIN CAPITAL LETTER B + COMBINING LONG DOUBLE SOLIDUS OVERLAY || U+0042 U+20EB
|-
| B⃦ ||
*Pros: Similar to current bitcoin.org logo
|| LATIN CAPITAL LETTER B + COMBINING DOUBLE VERTICAL STROKE OVERLAY || U+0042 U+20E6
|-
| ⓑ ||
*Pros: Small b represent the unit bit in computer where capital B is Byte
* Cons: Small fonts are harder to read
|| CIRCLED LATIN SMALL LETTER B || ||Alt +24D1
|-
|ᴃ|| || LATIN LETTER SMALL CAPITAL BARRED B || ||Alt +1D03
|-
|Ƀ||
*Pros: [http://www.ecogex.com/bitcoin/ See the project Ƀ Another Bitcoin identity]
|| LATIN CAPITAL LETTER B WITH STROKE || ||Alt +0243
|-
|B⃦|| || || ||
|-
|␢|| || (Unicode Block: Control Pictures) BLANK SYMBOL (graphic for space) || || Alt +2422
|-
|-
| 币 || pronounced "bi", combines "b", turned "c" and "T", many Chinese users, also 网民币 - Wangminbi, "The Netizen's Currency" (pun on Renminbi) || Chinese for "Currency" || || U+5E01
|-
| β ||
*Pros: Fluid look and easy to write; Lowercase<br/>
*Cons: Languages that use this character don't consider it a B. in Greek it's a V, and the German character it resembles is a hard S.
|| GREEK SMALL LETTER BETA || ||Alt +03B2
|-
|¤|| || CURRENCY SIGN ||Alt 0164 ||Alt +00A4
|-
|Ƅ|| || LATIN CAPITAL LETTER TONE SIX || ||Alt +0184
|-
|∄|| || (Unicode Block: Mathematical Operators) THERE DOES NOT EXIST || ||Alt +2204
|-
|ઘ|| || GUJARATI LETTER GHA (Indo-Aryan language) || ||Alt +0A98
|-
|ϭ|| || (Unicode Block: Greek and Coptic) COPTIC SMALL LETTER SHIMA || ||Alt +03ED
|-
| ɸ || contains 0 and I || Greek small Phi || || U+0278
|-
| ∆ || delta for "digital" || Greek capital Delta. (In Greek it's pronounced as the "th" in "then" and not like "d" in "digital". || || U+0394
|-
|[[Image:Bitcoin Symbol Suggestion circled struck-through B.png|20px]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|[[Image:Bitcoin Symbol Suggestion rotated power.png|20px]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|ⓢ|| Purposed as a smaller unit of bitcoin. E.g. A hundredth of a bitcoin || CIRCLED LATIN SMALL LETTER S || || Alt +24E2
|-
|≡ || three bars like three bits
cons: this resembles the letter ksi (Ξ) in Greek and it sounds like "x" in "axiom". || || || Alt + 240
|-
|[[Image:Bat.png|32x32px|alt=The b'at]]
the b'at
||
* Pros: Is round like a coin. Contains the B for Bitcoin. Borrows a style widelly associated with the internet. Not used for other meanings.
* Cons: Does not exist in the Unicode standard
* Cons: Very similar to the existing trademarked Broad logo [[http://www.broad.com/]]
|| || ||
|-
|A 'C' with '1' and '0' inside [[http://img829.imageshack.us/img829/8840/bitcoinlogodraft.png]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|A 'C' with a 'circle' and 'dot' inside [[http://img836.imageshack.us/img836/6006/bitcoinlogodraftii.png]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
| ◪|| || (Unicode Block: Geometric Shapes) SQUARE WITH LOWER RIGHT DIAGONAL HALF BLACK || || Alt +25EA
|-
|[[http://hosting11.imagecross.com/image-hosting-61/2381unicode1s.png]][[http://hosting11.imagecross.com/image-hosting-61/162bitcoin_uni_s.png]]||
* Cons: Does not exist in the Unicode standard
|| || ||
|-
|☺|| ||WHITE SMILING FACE|| || Alt +263A
|-
|☻|| ||BLACK SMILING FACE|| || Alt +263B
|-
|㋡|| ||CIRCLED KATAKANA TU' (Japanese)|| || Alt +32E1
|-
|ᗸ|| Ressembles the striked B while being different from Baht symbol ||CANADIAN SYLLABICS CARRIER KHEE || || Alt +15F8
|}

[[Category:Introduction]]

Category:History

2012-09-20T21:44:00Z

Garyrowe: /* 2011 */

== Important milestones of the Bitcoin project ==
=== 2008 ===
{| style="text-align: left"
|-
! width="8em" | August 18
|| Domain name "bitcoin.org" registered<ref>[https://bitcointalk.org/index.php?topic=103369.msg1135218#msg1135218 According to theymos], Satoshi registered bitcoin.org via https://www.anonymousspeech.com/ which allows to anonymously register domains.</ref>.
|-
! October 31
|| [http://article.gmane.org/gmane.comp.encryption.general/12588/ Bitcoin design paper] published
|-
! November 09
|| Bitcoin project registered at SourceForge.net
|}

=== 2009 ===
{| style="text-align: left"
|-
! width="8em" | January 3
|| [http://www.BlockExplorer.com/b/0 Genesis block] established at 18:15:05 GMT
|-
! January 11
|| Bitcoin v0.1 released and announced on the [http://www.mail-archive.com/cryptography@metzdowd.com/msg10152.html cryptography mailing list]
|-
! January 12
|| First Bitcoin transaction, [http://www.BlockExplorer.com/b/170 in block 170] - from [[Satoshi]] to Hal Finney<ref>[http://bitcointalk.org/index.php?topic=91806.msg1012234#msg1012234 Earliest Block With A Spend]</ref>.
|-
! October 5
|| Exchange rates [http://newlibertystandard.wetpaint.com/page/2009+Exchange+Rate published] by New Liberty Standard. $1 = 1,309.03 BTC (and [[User:theymos|theymos]] thought NLS was overcharging<ref>[http://bitcointalk.org/index.php?topic=104287.msg1143955#msg1143955 Historical Price Data for 2009]</ref>)
|-
! December 16
|| Bitcoin v0.2 released
|-
! December 30
|| First difficulty increase at 06:11:04 GMT
|}

=== 2010 ===
{| style="text-align: left"
|-
! width="8em" | February 6
|| [[Bitcoin Market]] established
|-
! May 22
|| laszlo first to buy pizza with Bitcoins agreeing upon paying 10,000 BTC for ~$25 worth of pizza courtesy of jercos<ref>[https://bitcointalk.org/index.php?topic=137.msg1195#msg1195 bitcointalk post] where laszlo confirmed having bought pizza</ref>
|-
! July 7
|| Bitcoin v0.3 released
|-
! July 11
|| Bitcoin v0.3 release mentioned on slashdot<ref>[http://news.slashdot.org/story/10/07/11/1747245/Bitcoin-Releases-Version-03 slashdot] metiones Bitcoin</ref>, bringing a large influx of new bitcoin users.
|-
! July 12
|| Beginning of a 10x increase in exchange value over a 5 day period, from about $0.008/BTC to $0.08/BTC
|-
! July 17
|| [[MtGox]] established
|-
! July 18
|| ArtForz generated his first block after establishing his personal OpenCL GPU hash farm
|-
! August 15
|| Bug in the bitcoin code allows a bad transaction into block 74638. Users quickly adopt fixed code and the "good" block chain overtook the bad one at a block height of 74691, 53 blocks later ([[Incidents#Value_overflow]]).
|-
! September 14
|| jgarzik [https://bitcointalk.org/index.php?topic=133.msg12921#msg12921 offered] 10,000 BTC (valued at ~$600-650) to puddinpop to open source their windows-based CUDA client
|-
! September 18
|| puddinpop [https://bitcointalk.org/index.php?topic=133.msg13135#msg13135 released] source to their windows-based CUDA client under MIT license
|-
! September 29
|| kermit [https://bitcointalk.org/index.php?topic=1306.0 discovered] a microtransactions exploit which precipitated the Bitcoin v0.3.13 release
|-
! October 01
|| First public OpenCL miner released
|-
! October 04
|| Original Bitcoin History wiki page (this page) established (ooh so meta) on Bitcoin.org's wiki.
|-
! October 07
|| Exchange rate started climbing up from $0.06/BTC after several flat months.
|-
! October 28
|| First bitcoin short sale transaction initiated, with a loan of 100 BTC by nanotube to [[User:Kiba|kiba]], facilitated by the [[Bitcoin-otc|#bitcoin-otc]] market.
|-
! November 6
|| The [https://bitcointalk.org/index.php?topic=1672 Bitcoin economy passed US $1 million]. The MtGox price touched USD $0.50/BTC.
|-
! December 7
|| Bitcoind was compiled for the Nokia N900 mobile computer by doublec. The following day, ribuck sent him 0.42 BTC in the first portable-to-portable Bitcoin transaction.
|-
! December 9
|| The generation difficulty passed 10,000.
|-
|
|| First bitcoin call option contract sold, from nanotube to [[User:Sgornick|sgornick]], via the [[Bitcoin-otc|#bitcoin-otc]] market.
|-
! December 16
|| [http://mining.bitcoin.cz/ Bitcoin Pooled Mining], operated by slush, found its first block
|}

=== 2011 ===
{| style="text-align: left"
|-
! January 2
|| [[Tonal Bitcoin]] units standardized.
|-
! width="8em" | January 8
|| [[History of Bitcoin]] page (this page) created after replicating from original Bitcoin History page on Bitcoin.org.
|-
|
|| Bitcoin Pooled Mining reached a total of 10,000 Mhash/s
|-
! January 27
|| Largest numeric value ever traded for bitcoins thus far occurred on this date. Three currency bills from Zimbabwe, known as Zimdollars, were traded on [[Bitcoin-otc|#bitcoin-otc]] at the rate of 4 BTC for each of the one-hundred trillion dollar ($100,000,000,000,000) Zimbabwe notes<ref>Serial numbers for Zimdollars sold: AA1669317, AA1669318 and AA1669319</ref>
|-
! January 28
|| Block 105000 was generated. This means that 5.25 million bitcoins have been generated, which is just over one-quarter of the eventual total of nearly 21 million.
|-
! February 9
|| Bitcoin reached parity with the US dollar, touching $1 per BTC at [[MtGox]].
|-
! February 10
|| Bitcoin.org website struggles to handle [https://bitcointalk.org/index.php?topic=3444.0 traffic] resulting from mentions on Slashdot<ref>[http://news.slashdot.org/story/11/02/10/189246/Online-Only-Currency-BitCoin-Reaches-Dollar-Parity Online-Only Currency BitCoin Reaches Dollar Parity]</ref>, Hacker News and Twitter following the news that parity had been reached.
|-
! February 14
|| A vehicle was, for the first time, offered in exchange for a certain number of bitcoins<ref>[https://bitcointalk.org/index.php?topic=3485.0 Car for Sale - Australia]</ref>.
|-
! March 6
|| Total Bitcoin network computation speed for a short time reached a new high of almost 900Ghash/sec, dropping to 500Ghash/sec soon after. Some speculate that this was due to some supercomputer or bot-net that joined the network ([http://bitcoin.atspace.com/mysteryminer.html mystery miner]).
|-
! March 18
|| BTC/USD exchange rate reaches a 6-week low point at almost $0.70/BTC, after what appeared to be a short burst of, possibly automated, BTC sales at progressively lower prices. BTC price had been declining since the February 9 high.
|-
! March 25
|| Difficulty decreased nearly 10%. A decrease has only occurred once before, and this decrease of nearly 10% was the largest.
|-
! March 27
|| The first market for exchanging bitcoins to and from the British Pound Sterling BTC/GBP, [[Britcoin]], opens.
|-
! March 31
|| The first market for exchanging bitcoins to and from Brazilian Reals, [[Bitcoin Brazil]], opens.
|-
! April 5
|| The first market for exchanging bitcoins to and from the Polish złoty, [[BitMarket.eu]], opens.
|-
! April 12
|| First bitcoin put option contract sold via the [[Bitcoin-otc|#bitcoin-otc]] market.
|-
! April 16
|| TIME does [http://techland.time.com/2011/04/16/online-cash-bitcoin-could-challenge-governments/ an article on Bitcoin].
|-
! April 23
|| BTC/USD exchange rate reaches and passes parity with the Euro (EUR) on [[MtGox]] exchange.
|-
|
|| BTC/USD exchange rate reaches and passes parity with the British Sterling Pound (GBP) on [[MtGox]] exchange.
|-
|
|| Value of the Bitcoin money stock at current exchange rate passes $10 million USD threshold.
|-
! April 27
|| [[VirWoX]] opens first market to trade bitcoins against a virtual currency on BTC/SL (Second Life Lindens) exchange.
|-
! April 28
|| Block [http://blockexplorer.com/b/120630 120,630] is first to be mined using split allocation of the generation reward.
|-
! April 30
|| The generation difficulty passed 100,000.
|-
! June 2
|| The exchange rate at [[MtGox]] touched 10 USD per BTC.
|-
! June 3
|| [[Tonal Bitcoin]] reached parity with the US cent, touching 1¢ per TBC at [[Bitcoin Market]].
|-
! June 8
|| The [[MtGox]] exchange rate peaked at 31.91 USD, at a "market capitalization" of about $206 M [http://bitcoin.stackexchange.com/questions/2047/market-capitalization-over-time].
|-
! June 12
|| The [[MtGox]] exchange rate briefly dropped to near 10 USD four days after the peak, in its largest percentage price retreat to date.
|-
! June 13
|| Forum user allinvain claimed to have had [http://forum.bitcoin.org/index.php?topic=16457.0 25,000 BTC stolen] from his Bitcoin wallet (approx. USD equivalent $375,000).
|-
! June 19
|| The MtGox database was compromised and the user table was leaked, containing details of 60,000 usernames, email addresses and password hashes, some of which were based on a highly vulnerable hashing algorithm.
|-
! June 19
|| Someone was able to access an admin account at MtGox and issue sell orders for hundreds of thousands of fake bitcoins, forcing the MtGox price down from $17.51 per bitcoin to $0.01. MtGox announced that these trades would be reversed. Trading was halted at MtGox for 7 days (and also briefly at TradeHill and Britcoin while their security was reviewed).
|-
! June 19
|| Some of the users on the leaked MtGox database had used the same username at MyBitcoin and had their passwords hacked. About 600 of them had their balance [http://forum.bitcoin.org/index.php?topic=22221.msg279396#msg279396 stolen from their MyBitcoin accounts]. One user lost over 2000 BTC.
|-
! June 20
|| The EFF announced that it was no longer accepting Bitcoin donations due to legal uncertainties.
|-
! June 24
|| The generation difficulty passed 1,000,000 with Block [http://blockexplorer.com/b/133056 133056].
|-
! July 19
|| "Let it go on record that at 4:05pm CET [19 July 2011], my manager Tadek was the first person in the world to receive [testnet] Bitcoins via NFC ;)" - Mike Hearn
|-
! July 22
|| [[BitCoins Mobile]], the first Bitcoin application for iPad was released by [http://www.intervex.net Intervex Digital].
|-
! August 20
|| First Bitcoin Conference and World Expo held, in NYC.
|-
! August 23
|| [[P2Pool]], the first P2P decentralized pool, mines its first Bitcoin mainnet block (Block [http://blockexplorer.com/b/142312 142,312]).
|-
! August 30
|| Difficulty adjustment at block [http://blockexplorer.com/b/143136 143,136] marks the first back-to-back drop.
|-
! November 15
|| First CVE (CVE-2011-4447) assigned to a Bitcoin client exploit.
|-
! November 25
|| First European Bitcoin Conference in Prague, Czech Rep.
|-
! December 12
|| Largest amount of fees, to-date, in a single transaction, and most fees in a single block. A [http://blockexplorer.com/tx/1d7749c65c90c32f5e2c036217a2574f3f4403da39174626b246eefa620b58d9 transaction] paid 171 BTC in fees in [http://blockexplorer.com/b/157235 block 157235]<ref>[http://bitcointalk.org/index.php?topic=88423.msg973509#msg973509 Largest fee ever?]</ref>.
|}

=== 2012 ===
{| style="text-align: left"
|-
! width="8em" | March 1
|| Largest theft of bitcoins to-date occurred (near 50K BTC) after security breach at web host Linode.
|-
! May 08
|| A single service, [[SatoshiDICE]] becomes responsible for over half the transaction volume on the Bitcoin blockchain.
|-
! June 3
|| Largest block (most transactions), to-date (June 3), is [http://BlockExplorer.com/b/181919 block 181919] with 1322 transactions<ref>[http://bitcointalk.org/index.php?topic=85353.msg939859#msg939859 Largest block to date]</ref>.
|-
! July 22
|| One millionth topic reply was posted on the unofficial [[Bitcoin Forum]] <ref>[https://bitcointalk.org/index.php?topic=94608.0 Topic about one millionth forum post]</ref>.
|}

==See Also==

* [[Bitcoin Firsts]]

==References==
<references />

People

2012-08-11T10:27:31Z

Garyrowe: Updated Gary Rowe's profile

A list of active contributors to Bitcoin, ordered by first name.

[[Andreas Schildbach]] ([https://profiles.google.com/andreas.schildbach Profile]) - original developer of [https://market.android.com/details?id=de.schildbach.wallet Bitcoin Wallet for Android] ([http://code.google.com/p/bitcoin-wallet/ Google Code Project]).

[[Amir Taaki]] aka genjix- creator of the [[Britcoin]] and [[Intersango]] exchanges, [[libbitcoin]] library for Bitcoin, [[Spesmilo]], [[Bitcoin Consultancy]], [[Vibanko]], [[GLBSE]] client, Bitcoin poker client, [https://gitorious.org/freecoin/freecoin Python bindings] for Bitcoin, [[Pastecoin]] and others.

[[ArtForz|Art Forz]]- developed the first GUI miner and at one time his GPU mining farm (the ArtFarm) was mining over a third of all blocks.

[[Gary Rowe]] [https://plus.google.com/u/0/115295932487523951663/about (Profile)] - Contributor to the [[MultiBit]] (http://multibit.org) and [[BitCoinJ]] (http://code.google.com/p/bitcoinj/) projects. Working on various Bitcoin based businesses.

[[Gavin Andresen]]- [https://profiles.google.com/u/0/gavinandresen/about (Profile)] [[Satoshi client]] maintainer. He previously worked at Silicon Graphics and now runs his own company.

[[Hal Finney]]- one of the creators of [http://en.wikipedia.org/wiki/Pretty_Good_Privacy PGP] and one of the earliest contributors to the Bitcoin project. First to identify a type of double-spending attack that now bears his name -- the [[Double-spending#Finney_attack|Finney attack]].

James McCarthy aka Nefario- creator of the first bitcoin stock exchange [[GLBSE]]

[[Jed McCaleb]], original developer of MtGox. Previously created eDonkey2000.

[[Jeff Garzik]]- [http://en.wikipedia.org/wiki/Jeff_Garzik (Wikipedia Entry)] [[Satoshi client]] core developer, GPU poold software and the founder of [[Bitcoin Watch]]. Works as a Linux kernel developer at Red Hat,

[[Luke Dashjr]] aka Luke-Jr- [[Eligius]] owner/admin and [[Spesmilo]] core developer

[[Mark Karpeles]] aka MagicalTux- Owner of the largest Bitcoin exchange, [[MtGox]], this Bitcoin Wiki, and [https://www.kalyhost.com/ Kalyhost]

[[Sirius|Martti Malmi]] aka Sirius- Operates the host for bitcoin.org and is an administrator of the [[Bitcoin Forum]].

[[Matt Corallo]] aka BlueMatt- [[Satoshi client]] developer.

[[Michael Hendrix]] aka mndrix- creator of the now defunct CoinPal and CoinCard services

[[Michael Marquardt]] aka theymos- creator of the widely used blockexplorer.com site, and BitcoinTalk Forum

[[Mike Hearn]] [https://profiles.google.com/mh.in.england/about (Profile)]- Google engineer who works on Gmail and developed [[BitCoinJ]] (http://code.google.com/p/bitcoinj/)

[[Nils Schneider]] aka tcatm - Bitcoin developer, owner of BitcoinWatch, creator and owner of BitcoinCharts, GPU mining software and JS web interface.

[[Patrick McFarland]] aka Diablo-D3 - DiabloMiner author, and BitcoinTalk forum moderator.

[[Patrick Strateman]] aka phantomcircuit - Bitcoin developer, creator of [[Intersango]], member of [[Bitcoin Consultancy]] and creator of Python Bitcoin implementation.

[[Pieter Wuille]] aka sipa- [[Satoshi client]] developer and maintainer of the network graphs http://bitcoin.sipa.be

[[Stefan Thomas]] aka justmoon- creator of the WeUseCoins.com site/video and WebCoin.

[[Vladimir Marchenko]]- [https://profiles.google.com/u/0/vmartchenko/about?hl=en Profile], runs [[Marchenko Ltd]] which sells mining contracts, previously developed the figator.org search engine.

==See Also==
* [[Original client developers]]
* [[Developers]]
* Wiki list of [[:Special:ListUsers|users]]
* [[Bitcoin:Community_portal|Community portal]]
* [[:Category:People]]

Differences between Bitcoin and Monopoly Money

2012-08-03T11:47:56Z

Garyrowe:

New people encountering Bitcoin often think that it is rather similar to Monopoly Money. It is just some meaningless tokens exchanged between people with no "real" value.

This article is meant to explain the differences in a newb-friendly manner.

TL;DR - Bitcoins are valuable because people think they are valuable. This does not mean they are a "monopoly currency", any more than other currencies.

== There is a finite (rather small) amount of Bitcoins ==
There will never be more than 21,000,000 Bitcoins, while there is a lot of MM, and the company selling Monopoly can always print more.

== Empirical Evidence ==
It is an empiric fact that Bitcoins are valuable (if you think otherwise, please sell me some for 0.1$ each .. you'll be "ripping me off" since you know they're worthless, right?)

Bitcoins are exchanged today for goods, services and other currencies. It is foolish not to accept the truth - the statement "Today, Bitcoins have value" is a true one, while nobody can say the same for MM.

It is a bit of a self-sustaining prophecy ... but that doesn't make it false.

'''Some links:'''
* [https://en.bitcoin.it/wiki/Trade List of online and real world businesses that currently accept Bitcoin]
* [http://www.forbes.com/sites/jonmatonis/2012/07/31/top-10-bitcoin-statistics/ Top 10 Bitcoin statistics (2012)]. In particular:
** [http://blockchain.info/charts/market-cap Market Cap] and [http://bitcoincharts.com/charts/mtgoxUSD#tgSzm1g10zm2g25zvzl Price] (log scale!)
** [http://blockchain.info/charts/n-transactions Number of transactions]
** [http://bitcoin.sipa.be/ Total Network Hash Rate]
** [http://blockchain.info/charts/estimated-transaction-volume-usd Daily Transaction Volume in USD]

== Bitcoins are good as a means of exchange ==
http://bitcoin.stackexchange.com/questions/305/what-are-the-perceived-advantages-of-bitcoin-as-a-means-of-exchange

== Bitcoins are good in "storing value over time" ==
http://bitcoin.stackexchange.com/questions/2834/what-are-the-perceived-advantages-of-bitcoin-as-a-store-of-value

Empirical evidence, in the time period 2009-2012 at least, have shown them to be excellent store of value. This is not yet concrete proof that this trend will remain, but it's a start.

== Bitcoins are like fiat currencies ==
Fiat currencies (USD, Euro, ...) only have value because people believe they have value, and '''for no other reason'''. If everybody in the world suddenly thought the US was going to go into a major economic breakdown, then the value of USD would plummet, because it is only based on this belief (this process might be happening right now).

USD doesn't have value because "the US government backs it". There is no backing. It is not backed by bars of gold. It is not backed by other currencies (the US government does not promise they hold in their vaults 0.5 euro per every USD out there). '''This "backing" is a myth'''. The thing backing the US Dollar is the state of the US economy, and the thing backing Bitcoin is the state of the Bitcoin economy ('''speculation included!''').

[[Category:Introduction]]

People

2012-01-30T11:10:24Z

Garyrowe: correcting ordering

A list of active contributors to Bitcoin, ordered by first name.

[[Andreas Schildbach]] ([https://profiles.google.com/andreas.schildbach Profile]) - original developer of [https://market.android.com/details?id=de.schildbach.wallet Bitcoin Wallet for Android] ([http://code.google.com/p/bitcoin-wallet/ Google Code Project]).

[[Amir Taaki]] aka genjix- creator of the [[Britcoin]] and [[Intersango]] exchanges, [[libbitcoin]] library for Bitcoin, [[Spesmilo]], [[Bitcoin Consultancy]], [[Vibanko]], [[GLBSE]] client, Bitcoin poker client, [https://gitorious.org/freecoin/freecoin Python bindings] for Bitcoin, [[Pastecoin]] and others.

[[ArtForz|Art Forz]]- developed the first GUI miner and at one time his GPU mining farm (the ArtFarm) was mining over a third of all blocks.

[[Gary Rowe]] [http://gary-rowe.com (Profile)] - Contributor to the [[MultiBit]] (http://multibit.org) and [[BitCoinJ]] (http://code.google.com/p/bitcoinj/) projects.

[[Gavin Andresen]]- [https://profiles.google.com/u/0/gavinandresen/about (Profile)] [[Satoshi client]] maintainer. He previously worked at Silicon Graphics and now runs his own company.

[[Hal Finney]]- one of the creators of [http://en.wikipedia.org/wiki/Pretty_Good_Privacy PGP] and one of the earliest contributors to the Bitcoin project.

James McCarthy aka Nefario- creator of the first bitcoin stock exchange [[GLBSE]]

[[Jed McCaleb]], original developer of MtGox. Previously created eDonkey2000.

[[Jeff Garzik]]- [http://en.wikipedia.org/wiki/Jeff_Garzik (Wikipedia Entry)] [[Satoshi client]] core developer, GPU poold software and the founder of [[Bitcoin Watch]]. Works as a Linux kernel developer at Red Hat,

[[Luke Dashjr]] aka Luke-Jr- [[Eligius]] owner/admin and [[Spesmilo]] core developer

[[Mark Karpeles]] aka MagicalTux- Owner of the largest Bitcoin exchange, [[MtGox]], this Bitcoin Wiki, and [https://www.kalyhost.com/ Kalyhost]

[[Sirius|Martti Malmi]] aka Sirius- Operates the host for bitcoin.org and is an administrator of the [[Bitcoin Forum]].

[[Matt Corallo]] aka BlueMatt- [[Satoshi client]] developer.

[[Michael Hendrix]] aka mndrix- creator of the now defunct CoinPal and CoinCard services

[[Michael Marquardt]] aka theymos- creator of the widely used blockexplorer.com site, and BitcoinTalk Forum

[[Mike Hearn]] [https://profiles.google.com/mh.in.england/about (Profile)]- Google engineer who works on Gmail and developed [[BitCoinJ]] (http://code.google.com/p/bitcoinj/)

[[Nils Schneider]] aka tcatm - Bitcoin developer, owner of BitcoinWatch, creator and owner of BitcoinCharts, GPU mining software and JS web interface.

[[Patrick McFarland]] aka Diablo-D3 - DiabloMiner author, and BitcoinTalk forum moderator.

[[Patrick Strateman]] aka phantomcircuit - Bitcoin developer, creator of [[Intersango]], member of [[Bitcoin Consultancy]] and creator of Python Bitcoin implementation.

[[Pieter Wuille]] aka sipa- [[Satoshi client]] developer and maintainer of the network graphs http://bitcoin.sipa.be

[[Stefan Thomas]] aka justmoon- creator of the WeUseCoins.com site/video and WebCoin.

[[Vladimir Marchenko]]- [https://profiles.google.com/u/0/vmartchenko/about?hl=en Profile], runs [[Marchenko Ltd]] which sells mining contracts, previously developed the figator.org search engine.

==See Also==
* [[Original client developers]]
* [[Developers]]
* Wiki list of [[:Special:ListUsers|users]]
* [[Bitcoin:Community_portal|Community portal]]
* [[:Category:People]]

People

2012-01-30T11:08:30Z

Garyrowe: Alphabetical ordering

[[Andreas Schildbach]] ([https://profiles.google.com/andreas.schildbach Profile]) - original developer of [https://market.android.com/details?id=de.schildbach.wallet Bitcoin Wallet for Android] ([http://code.google.com/p/bitcoin-wallet/ Google Code Project]).

[[Amir Taaki]] aka genjix- creator of the [[Britcoin]] and [[Intersango]] exchanges, [[libbitcoin]] library for Bitcoin, [[Spesmilo]], [[Bitcoin Consultancy]], [[Vibanko]], [[GLBSE]] client, Bitcoin poker client, [https://gitorious.org/freecoin/freecoin Python bindings] for Bitcoin, [[Pastecoin]] and others.

[[ArtForz|Art Forz]]- developed the first GUI miner and at one time his GPU mining farm (the ArtFarm) was mining over a third of all blocks.

[[Gary Rowe]] [http://gary-rowe.com (Profile)] - Contributor to the [[MultiBit]] (http://multibit.org) and [[BitCoinJ]] (http://code.google.com/p/bitcoinj/) projects.

[[Gavin Andresen]]- [https://profiles.google.com/u/0/gavinandresen/about (Profile)] [[Satoshi client]] maintainer. He previously worked at Silicon Graphics and now runs his own company.

[[Hal Finney]]- one of the creators of [http://en.wikipedia.org/wiki/Pretty_Good_Privacy PGP] and one of the earliest contributors to the Bitcoin project.

[[Jed McCaleb]], original developer of MtGox. Previously created eDonkey2000.

[[Jeff Garzik]]- [http://en.wikipedia.org/wiki/Jeff_Garzik (Wikipedia Entry)] [[Satoshi client]] core developer, GPU poold software and the founder of [[Bitcoin Watch]]. Works as a Linux kernel developer at Red Hat,

[[Luke Dashjr]] aka Luke-Jr- [[Eligius]] owner/admin and [[Spesmilo]] core developer

[[Mark Karpeles]] aka MagicalTux- Owner of the largest Bitcoin exchange, [[MtGox]], this Bitcoin Wiki, and [https://www.kalyhost.com/ Kalyhost]

[[Sirius|Martti Malmi]] aka Sirius- Operates the host for bitcoin.org and is an administrator of the [[Bitcoin Forum]].

[[Matt Corallo]] aka BlueMatt- [[Satoshi client]] developer.

[[Michael Hendrix]] aka mndrix- creator of the now defunct CoinPal and CoinCard services

[[Michael Marquardt]] aka theymos- creator of the widely used blockexplorer.com site, and BitcoinTalk Forum

[[Mike Hearn]] [https://profiles.google.com/mh.in.england/about (Profile)]- Google engineer who works on Gmail and developed [[BitCoinJ]] (http://code.google.com/p/bitcoinj/)

[[Nils Schneider]] aka tcatm - Bitcoin developer, owner of BitcoinWatch, creator and owner of BitcoinCharts, GPU mining software and JS web interface.

[[Patrick McFarland]] aka Diablo-D3 - DiabloMiner author, and BitcoinTalk forum moderator.

[[Patrick Strateman]] aka phantomcircuit - Bitcoin developer, creator of [[Intersango]], member of [[Bitcoin Consultancy]] and creator of Python Bitcoin implementation.

[[Pieter Wuille]] aka sipa- [[Satoshi client]] developer and maintainer of the network graphs http://bitcoin.sipa.be

[[Stefan Thomas]] aka justmoon- creator of the WeUseCoins.com site/video and WebCoin.

[[Vladimir Marchenko]]- [https://profiles.google.com/u/0/vmartchenko/about?hl=en Profile], runs [[Marchenko Ltd]] which sells mining contracts, previously developed the figator.org search engine.

James McCarthy aka Nefario- creator of the first bitcoin stock exchange [[GLBSE]]

==See Also==
* [[Original client developers]]
* [[Developers]]
* Wiki list of [[:Special:ListUsers|users]]
* [[Bitcoin:Community_portal|Community portal]]
* [[:Category:People]]

People

2012-01-30T11:07:32Z

Garyrowe: Adding myself to the list

[[Andreas Schildbach]] ([https://profiles.google.com/andreas.schildbach Profile]) - original developer of [https://market.android.com/details?id=de.schildbach.wallet Bitcoin Wallet for Android] ([http://code.google.com/p/bitcoin-wallet/ Google Code Project]).

[[Amir Taaki]] aka genjix- creator of the [[Britcoin]] and [[Intersango]] exchanges, [[libbitcoin]] library for Bitcoin, [[Spesmilo]], [[Bitcoin Consultancy]], [[Vibanko]], [[GLBSE]] client, Bitcoin poker client, [https://gitorious.org/freecoin/freecoin Python bindings] for Bitcoin, [[Pastecoin]] and others.

[[ArtForz|Art Forz]]- developed the first GUI miner and at one time his GPU mining farm (the ArtFarm) was mining over a third of all blocks.

[[Gavin Andresen]]- [https://profiles.google.com/u/0/gavinandresen/about (Profile)] [[Satoshi client]] maintainer. He previously worked at Silicon Graphics and now runs his own company.

[[Hal Finney]]- one of the creators of [http://en.wikipedia.org/wiki/Pretty_Good_Privacy PGP] and one of the earliest contributors to the Bitcoin project.

[[Jed McCaleb]], original developer of MtGox. Previously created eDonkey2000.

[[Jeff Garzik]]- [http://en.wikipedia.org/wiki/Jeff_Garzik (Wikipedia Entry)] [[Satoshi client]] core developer, GPU poold software and the founder of [[Bitcoin Watch]]. Works as a Linux kernel developer at Red Hat,

[[Luke Dashjr]] aka Luke-Jr- [[Eligius]] owner/admin and [[Spesmilo]] core developer

[[Mark Karpeles]] aka MagicalTux- Owner of the largest Bitcoin exchange, [[MtGox]], this Bitcoin Wiki, and [https://www.kalyhost.com/ Kalyhost]

[[Sirius|Martti Malmi]] aka Sirius- Operates the host for bitcoin.org and is an administrator of the [[Bitcoin Forum]].

[[Matt Corallo]] aka BlueMatt- [[Satoshi client]] developer.

[[Michael Hendrix]] aka mndrix- creator of the now defunct CoinPal and CoinCard services

[[Michael Marquardt]] aka theymos- creator of the widely used blockexplorer.com site, and BitcoinTalk Forum

[[Mike Hearn]] [https://profiles.google.com/mh.in.england/about (Profile)]- Google engineer who works on Gmail and developed [[BitCoinJ]] (http://code.google.com/p/bitcoinj/)

[[Nils Schneider]] aka tcatm - Bitcoin developer, owner of BitcoinWatch, creator and owner of BitcoinCharts, GPU mining software and JS web interface.

[[Patrick McFarland]] aka Diablo-D3 - DiabloMiner author, and BitcoinTalk forum moderator.

[[Patrick Strateman]] aka phantomcircuit - Bitcoin developer, creator of [[Intersango]], member of [[Bitcoin Consultancy]] and creator of Python Bitcoin implementation.

[[Pieter Wuille]] aka sipa- [[Satoshi client]] developer and maintainer of the network graphs http://bitcoin.sipa.be

[[Stefan Thomas]] aka justmoon- creator of the WeUseCoins.com site/video and WebCoin.

[[Vladimir Marchenko]]- [https://profiles.google.com/u/0/vmartchenko/about?hl=en Profile], runs [[Marchenko Ltd]] which sells mining contracts, previously developed the figator.org search engine.

James McCarthy aka Nefario- creator of the first bitcoin stock exchange [[GLBSE]]

[[Gary Rowe]] [http://gary-rowe.com (Profile)] - Contributor to the [[MultiBit]] (http://multibit.org) and [[BitCoinJ]] (http://code.google.com/p/bitcoinj/) projects.

==See Also==
* [[Original client developers]]
* [[Developers]]
* Wiki list of [[:Special:ListUsers|users]]
* [[Bitcoin:Community_portal|Community portal]]
* [[:Category:People]]

Help:FAQ

2011-06-10T22:48:47Z

Garyrowe: /* What do I call the various denominations of Bitcoins? */

Here you will find answers to the most commonly asked questions.

== General ==
=== What are bitcoins? ===
Bitcoins are the unit of currency of the Bitcoin system. A commonly used shorthand for this is “BTC” to refer to a price or amount (eg: “100 BTC”).
A Bitcoin isn't tangible. It is just a number associated with a [[Address|Bitcoin Address]]. See also an [[Introduction|easy intro]] to bitcoin.

=== How can I get Bitcoins? ===

There are five ways to get Bitcoins:

* Buy them on an exchange such as [https://www.mtgox.com/ Mt. Gox] or [http://www.bitcoin-otc.com/ #bitcoin-otc] on FreeNode.
* Accept Bitcoins as payment for goods or services.
* Find a local trader on [http://tradebitcoin.com tradebitcoin] (or somewhere else) and trade with him in cash.
* Create a new [[block]] (currently yields 50 Bitcoins).
* Participate in a [[Pooled mining|mining pool]].

=== Can I buy Bitcoins with Paypal? ===

While it's possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most major 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 goods. Paypal too often sides with the fraudulent buyer in this case, and so exchangers no longer allow this method of funding.

Buying Bitcoins from individuals with this method is still possible, but requires mutual trust. In this case, Bitcoin seller beware.

=== How are new Bitcoins created? ===

[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]
New coins are generated by a network node each time it finds the solution to a certain mathematical problem (i.e. creates a new [[block]]), which is difficult to perform and can demonstrate a [[proof of work]]. The reward for solving a block is [[controlled inflation|automatically adjusted]] so that in the first 4 years of the Bitcoin network, 10,500,000 BTC will be created. The amount is halved each 4 years, so it will be 5,250,000 over years 4-8, 2,625,000 over years 8-12 and so on. Thus the total number of coins will approach 21,000,000 BTC over time.

In addition, built into the network is a system that attempts to allocate new coins in blocks about every 10 minutes, on average, somewhere on the network. As the number of people who attempt to generate these new coins changes, the difficulty of creating new coins changes. This happens in a manner that is agreed upon by the network as a whole, based upon the time taken to generate the previous 2016 blocks. The difficulty is therefore related to the average computing resources devoted to generate these new coins over the time it took to create these previous blocks. The likelihood of somebody "discovering" one of these blocks is based on the computer they are using compared to all of the computers also generating blocks on the network.

=== What's the current total number of Bitcoins in existence? ===

[http://blockexplorer.com/q/totalbc Current count]

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 210,000 blocks, 25 BTC for the next 210,000 blocks, then 12.5 BTC, 6.25 BTC and so on.

=== How divisible are Bitcoins? ===

Technically, a Bitcoin can be divided down to 8 decimals using existing data structures, so 0.00000001 BTC is the smallest amount currently possible. Discussions about and ideas for ways to provide for even smaller quantities of Bitcoins may be created in the future if the need for them ever arises.

=== What do I call the various denominations of Bitcoins? ===
There is a lot of discussion about the naming of these fractions of Bitcoins. The leading candidates are the SI unit approach and the normalised approach which are covered in more detail below.

==== The SI unit approach ====

* 1 BTC = 1 Bitcoin
* 0.001 BTC = 1 Milli Bitcoin or mbit (pronounced em-bit) or millibit
* 0.000 001 BTC = 1 Micro Bitcoin or ubit (pronounced yu-bit) or microbit
* 0.000 000 001 BTC = 1 Nano Bitcoin or nbit (pronounced en-bit) or nanobit (not currently supported but possible in the future)

The above follows the accepted international SI units for thousandths, millionths and billionths. 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't be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as "cent", "nickel", "dime", "pence", "pound", "kopek" and so on are to be discouraged. This is a worldwide currency.

One exception is the "satoshi" which is smallest denomination currently possible

* 0.000 000 01 BTC = 1 Satoshi (pronounced sa-toh-shee)

which is so named in honour of Satoshi Nakamoto the pseudonym of the inventor of Bitcoin.

==== The normalised approach ====
In the normalised approach the BTC is redefined to be 100 satoshis. This gives rise to a nomenclature that has the following form

* 0.01 BTC = 1 satoshi
* 1 BTC = 1 Bitcoin

This has the advantage that it closely follows the behaviour of existing currencies which do not have more than 2 decimal places to describe the smallest unit ( 0.01 USD = 1 cent, 0.01 GBP = 1 penny, 0.01 EUR = 1 eurocent). Further, this approach allows for instant comparison for larger values compared with the SI approach: "The price went from 1 BTC to 100 BTC overnight" against "The price went from 10 microbits to 1 millibit overnight".

Further discussion on this topic can be found on the forums here:

* [http://forum.bitcoin.org/index.php?topic=14438.msg195287#msg195287 We need names]
* [http://forum.bitcoin.org/index.php?topic=8282.0 What to call 0.001 BTC]

=== How does the halving work when the number gets really small? ===

The reward will go from 0.00000001 BTC to 0. Then no more coins will likely be created.

The calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by 2 and rounded down. The integer is equal to the value in BTC * 100,000,000. This is how all Bitcoin balances/values are stored internally.

Keep in mind that using current rules this will take nearly 100 years before it becomes an issue and Bitcoins may change considerably before that happens.

=== How long will it take to generate all the coins? ===

The last block that will generate coins will be block #6,929,999. This should be generated around year 2140. Then the total number of coins in circulation will remain static at 20,999,999.9769 BTC.

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 20999999.999999999496 BTC.

=== If no more coins are going to be generated, will more blocks be created? ===

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, what will sustain the ability to use bitcoins will be these fees entirely. There will be blocks generated after block #6,929,999, assuming that people are still using Bitcoins at that time.

=== But if no more coins are generated, what happens when Bitcoins are lost? Won't that be a problem? ===

Not at all. 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 when Bitcoins are lost, the remaining Bitcoins will increase in value to compensate. As the value of Bitcoins increase, the number of Bitcoins required to purchase an item '''de'''creases. This is known as a [[Deflationary spiral|deflationary economic model]]. Eventually, if and when it gets to the point where the largest transaction is less than 1BTC, then it's a simple matter of shifting the decimal place to the right a few places, and the system continues.

=== If every transaction is broadcast via the network, does BitCoin scale? ===
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.

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 couple of racks of machines using todays hardware). It's worth noting that the MasterCard network is structured somewhat like BitCoin itself - as a peer to peer broadcast network.

Learn more about [[Scalability]].

=== How does the BitCoin network handle [http://en.wikipedia.org/wiki/CAP_theorem the CAP theorem]? ===

=== Why do I have to wait 10 minutes before I can spend money I received? ===

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.

Blocks (shown as "confirmations" 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'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!

Why ten minutes specifically? It is a tradeoff chosen by Satoshi between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. If that made no sense to you, don't worry. Reading [http://www.bitcoin.org/bitcoin.pdf the technical paper] should make things clearer.

=== Do you have to wait 10 minutes in order to buy or sell things with BitCoin? ===

No, it's reasonable to sell things without waiting for a confirmation as long as the transaction is not of high value.

When people ask this question they are usually thinking about applications like supermarkets or snack machines, as discussed in [http://www.bitcoin.org/smf/index.php?topic=423.msg3819#msg3819 this thread from July 2010]. Zero confirmation transactions still show up in the GUI, but you cannot spend them. You can however reason about the risk involved in assuming you ''will'' be able to spend them in future. In general, selling things that are fairly cheap (like snacks, digital downloads etc) for zero confirmations will not pose a problem if you are running a well connected node.

=== Why does my Bitcoin address keep changing? ===

Whenever the address listed in "Your address" 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 ''Settings -> Your Receiving Addresses''.

==Economy==
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===
Bitcoins have value because they are accepted as payment by many. See the [[Trade|list of Bitcoin-accepting sites]].

When we say that a currency is backed up by gold, we mean that there's a promise in place that you can exchange the currency for gold. In a sense, you could say that Bitcoin is "backed up" by the price tags of merchants – a price tag is a promise to exchange goods for a specified amount of currency.

It's a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn'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't make anything valuable. For example, your fingerprints are scarce, but that doesn't mean they have any exchange value.

=== What if someone bought up all the existing Bitcoins? ===
What if somebody bought up all the gold in the world? Well, by attempting to buy it all, the buyer would just drive the prices up until he runs out of money.

Not all Bitcoins are for sale. Just as with gold, no one can buy a Bitcoin that isn't available for sale.

=== Bitcoin's monetary policy causes a deflationary spiral ===
See the article [[Deflationary spiral]].

=== Doesn't Bitcoin unfairly benefit early adopters? ===
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.

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.

=== Is Bitcoin a Ponzi scheme? ===
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.

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 profit from the usefulness of a stable and widely accepted p2p currency.

The fact that early adopters benefit more doesn't alone make anything a ponzi scheme. Apple stocks aren't ponzi even though the early investors got rich.

==Networking==
=== Do I need to configure my firewall to run bitcoin? ===

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. Bitcoin will also try to connect to IRC (tcp port 6667) to meet other nodes to connect to.

If you want to restrict your firewall rules to a few ips and/or don't want to allow IRC connection, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]]. If your provider blocks the common IRC ports, note that lfnet also listens on port 7777. Connecting to this alternate port currently requires either recompiling Bitcoin, or changing routing rules. For example, on Linux you can evade a port 6667 block by doing something like this:

echo 173.246.103.92 irc.lfnet.org >> /etc/hosts
iptables -t nat -A OUTPUT -p tcp --dest 173.246.103.92 --dport 6667 -j DNAT --to-destination :7777 -m comment --comment "bitcoind irc connection"

=== How does the peer finding mechanism work? ===
Bitcoin finds peers primarily by connecting to an IRC server (channel #bitcoin on irc.lfnet.org). If a connection to the IRC server cannot be established (like when connecting through TOR), an in-built node list will be used and the nodes will be queried for more node addresses.

==Mining==
===What is mining?===
Mining is the process of spending computation power to find valid blocks and thus create new Bitcoins.

Technically speaking, mining is the calculation of a [[hash]] of the previous block and a [[nonce]]. If the hash value is found to be less than the current [[difficulty]], a new block is formed and the miner gets 50 newly generated Bitcoins. If the hash is not less than the current difficulty, a new nonce is used, and a new hash is calculated. This is done thousands or millions of times per second by each miner.

===I've been mining for a long time and haven't created any new Bitcoins. What's wrong?===

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- or time-effective method of mining is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]). Since CPU mining is essentially useless, it may be removed from future versions of the Bitcoin software.

===Is mining used for some useful computation?===
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.

===Is it not a waste of energy?===
Spending energy on creating 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.

===Why don't we use calculations that are also useful for some other purpose?===
To provide security for the Bitcoin network, the calculations involved need to have some very specific features. These features are incompatible with leveraging the computation for other purposes.

==Help==
===I'd like to learn more. Where can I get help?===

* Read the [[Introduction|introduction to bitcoin]]
* See the videos, podcasts, and blog posts from the [[Press]]
* Read and post on the [[Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]
* Chat on one of the [[Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works

==See Also==

* [[Man page]]
* [[Introduction]]

[[de:FAQ]]
[[zh-cn:FAQ]]
[[fr:FAQ]]

[[Category:Technical]]
[[Category:Vocabulary]]

Help:FAQ

2011-06-10T22:47:16Z

Garyrowe: /* What do I call the various denominations of Bitcoins? */

Here you will find answers to the most commonly asked questions.

== General ==
=== What are bitcoins? ===
Bitcoins are the unit of currency of the Bitcoin system. A commonly used shorthand for this is “BTC” to refer to a price or amount (eg: “100 BTC”).
A Bitcoin isn't tangible. It is just a number associated with a [[Address|Bitcoin Address]]. See also an [[Introduction|easy intro]] to bitcoin.

=== How can I get Bitcoins? ===

There are five ways to get Bitcoins:

* Buy them on an exchange such as [https://www.mtgox.com/ Mt. Gox] or [http://www.bitcoin-otc.com/ #bitcoin-otc] on FreeNode.
* Accept Bitcoins as payment for goods or services.
* Find a local trader on [http://tradebitcoin.com tradebitcoin] (or somewhere else) and trade with him in cash.
* Create a new [[block]] (currently yields 50 Bitcoins).
* Participate in a [[Pooled mining|mining pool]].

=== Can I buy Bitcoins with Paypal? ===

While it's possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most major 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 goods. Paypal too often sides with the fraudulent buyer in this case, and so exchangers no longer allow this method of funding.

Buying Bitcoins from individuals with this method is still possible, but requires mutual trust. In this case, Bitcoin seller beware.

=== How are new Bitcoins created? ===

[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]
New coins are generated by a network node each time it finds the solution to a certain mathematical problem (i.e. creates a new [[block]]), which is difficult to perform and can demonstrate a [[proof of work]]. The reward for solving a block is [[controlled inflation|automatically adjusted]] so that in the first 4 years of the Bitcoin network, 10,500,000 BTC will be created. The amount is halved each 4 years, so it will be 5,250,000 over years 4-8, 2,625,000 over years 8-12 and so on. Thus the total number of coins will approach 21,000,000 BTC over time.

In addition, built into the network is a system that attempts to allocate new coins in blocks about every 10 minutes, on average, somewhere on the network. As the number of people who attempt to generate these new coins changes, the difficulty of creating new coins changes. This happens in a manner that is agreed upon by the network as a whole, based upon the time taken to generate the previous 2016 blocks. The difficulty is therefore related to the average computing resources devoted to generate these new coins over the time it took to create these previous blocks. The likelihood of somebody "discovering" one of these blocks is based on the computer they are using compared to all of the computers also generating blocks on the network.

=== What's the current total number of Bitcoins in existence? ===

[http://blockexplorer.com/q/totalbc Current count]

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 210,000 blocks, 25 BTC for the next 210,000 blocks, then 12.5 BTC, 6.25 BTC and so on.

=== How divisible are Bitcoins? ===

Technically, a Bitcoin can be divided down to 8 decimals using existing data structures, so 0.00000001 BTC is the smallest amount currently possible. Discussions about and ideas for ways to provide for even smaller quantities of Bitcoins may be created in the future if the need for them ever arises.

=== What do I call the various denominations of Bitcoins? ===

==== The SI unit approach ====
There is a lot of discussion about the naming of these fractions of Bitcoins. The leading candidates are:

* 1 BTC = 1 Bitcoin
* 0.001 BTC = 1 Milli Bitcoin or mbit (pronounced em-bit) or millibit
* 0.000 001 BTC = 1 Micro Bitcoin or ubit (pronounced yu-bit) or microbit
* 0.000 000 001 BTC = 1 Nano Bitcoin or nbit (pronounced en-bit) or nanobit (not currently supported but possible in the future)

The above follows the accepted international SI units for thousandths, millionths and billionths. 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't be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as "cent", "nickel", "dime", "pence", "pound", "kopek" and so on are to be discouraged. This is a worldwide currency.

One exception is the "satoshi" which is smallest denomination currently possible

* 0.000 000 01 BTC = 1 Satoshi (pronounced sa-toh-shee)

which is so named in honour of Satoshi Nakamoto the pseudonym of the inventor of Bitcoin.

==== The normalised approach ====
In the normalised approach the BTC is redefined to be 100 satoshis. This gives rise to a nomenclature that has the following form

* 0.01 BTC = 1 satoshi
* 1 BTC = 1 Bitcoin

This has the advantage that it closely follows the behaviour of existing currencies which do not have more than 2 decimal places to describe the smallest unit ( 0.01 USD = 1 cent, 0.01 GBP = 1 penny, 0.01 EUR = 1 eurocent). Further, this approach allows for instant comparison for larger values compared with the SI approach: "The price went from 1 BTC to 100 BTC overnight" against "The price went from 10 microbits to 1 millibit overnight".

Further discussion on this topic can be found on the forums here:

* [http://forum.bitcoin.org/index.php?topic=14438.msg195287#msg195287 We need names]
* [http://forum.bitcoin.org/index.php?topic=8282.0 What to call 0.001 BTC]

=== How does the halving work when the number gets really small? ===

The reward will go from 0.00000001 BTC to 0. Then no more coins will likely be created.

The calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by 2 and rounded down. The integer is equal to the value in BTC * 100,000,000. This is how all Bitcoin balances/values are stored internally.

Keep in mind that using current rules this will take nearly 100 years before it becomes an issue and Bitcoins may change considerably before that happens.

=== How long will it take to generate all the coins? ===

The last block that will generate coins will be block #6,929,999. This should be generated around year 2140. Then the total number of coins in circulation will remain static at 20,999,999.9769 BTC.

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 20999999.999999999496 BTC.

=== If no more coins are going to be generated, will more blocks be created? ===

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, what will sustain the ability to use bitcoins will be these fees entirely. There will be blocks generated after block #6,929,999, assuming that people are still using Bitcoins at that time.

=== But if no more coins are generated, what happens when Bitcoins are lost? Won't that be a problem? ===

Not at all. 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 when Bitcoins are lost, the remaining Bitcoins will increase in value to compensate. As the value of Bitcoins increase, the number of Bitcoins required to purchase an item '''de'''creases. This is known as a [[Deflationary spiral|deflationary economic model]]. Eventually, if and when it gets to the point where the largest transaction is less than 1BTC, then it's a simple matter of shifting the decimal place to the right a few places, and the system continues.

=== If every transaction is broadcast via the network, does BitCoin scale? ===
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.

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 couple of racks of machines using todays hardware). It's worth noting that the MasterCard network is structured somewhat like BitCoin itself - as a peer to peer broadcast network.

Learn more about [[Scalability]].

=== How does the BitCoin network handle [http://en.wikipedia.org/wiki/CAP_theorem the CAP theorem]? ===

=== Why do I have to wait 10 minutes before I can spend money I received? ===

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.

Blocks (shown as "confirmations" 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'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!

Why ten minutes specifically? It is a tradeoff chosen by Satoshi between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. If that made no sense to you, don't worry. Reading [http://www.bitcoin.org/bitcoin.pdf the technical paper] should make things clearer.

=== Do you have to wait 10 minutes in order to buy or sell things with BitCoin? ===

No, it's reasonable to sell things without waiting for a confirmation as long as the transaction is not of high value.

When people ask this question they are usually thinking about applications like supermarkets or snack machines, as discussed in [http://www.bitcoin.org/smf/index.php?topic=423.msg3819#msg3819 this thread from July 2010]. Zero confirmation transactions still show up in the GUI, but you cannot spend them. You can however reason about the risk involved in assuming you ''will'' be able to spend them in future. In general, selling things that are fairly cheap (like snacks, digital downloads etc) for zero confirmations will not pose a problem if you are running a well connected node.

=== Why does my Bitcoin address keep changing? ===

Whenever the address listed in "Your address" 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 ''Settings -> Your Receiving Addresses''.

==Economy==
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===
Bitcoins have value because they are accepted as payment by many. See the [[Trade|list of Bitcoin-accepting sites]].

When we say that a currency is backed up by gold, we mean that there's a promise in place that you can exchange the currency for gold. In a sense, you could say that Bitcoin is "backed up" by the price tags of merchants – a price tag is a promise to exchange goods for a specified amount of currency.

It's a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn'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't make anything valuable. For example, your fingerprints are scarce, but that doesn't mean they have any exchange value.

=== What if someone bought up all the existing Bitcoins? ===
What if somebody bought up all the gold in the world? Well, by attempting to buy it all, the buyer would just drive the prices up until he runs out of money.

Not all Bitcoins are for sale. Just as with gold, no one can buy a Bitcoin that isn't available for sale.

=== Bitcoin's monetary policy causes a deflationary spiral ===
See the article [[Deflationary spiral]].

=== Doesn't Bitcoin unfairly benefit early adopters? ===
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.

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.

=== Is Bitcoin a Ponzi scheme? ===
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.

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 profit from the usefulness of a stable and widely accepted p2p currency.

The fact that early adopters benefit more doesn't alone make anything a ponzi scheme. Apple stocks aren't ponzi even though the early investors got rich.

==Networking==
=== Do I need to configure my firewall to run bitcoin? ===

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. Bitcoin will also try to connect to IRC (tcp port 6667) to meet other nodes to connect to.

If you want to restrict your firewall rules to a few ips and/or don't want to allow IRC connection, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]]. If your provider blocks the common IRC ports, note that lfnet also listens on port 7777. Connecting to this alternate port currently requires either recompiling Bitcoin, or changing routing rules. For example, on Linux you can evade a port 6667 block by doing something like this:

echo 173.246.103.92 irc.lfnet.org >> /etc/hosts
iptables -t nat -A OUTPUT -p tcp --dest 173.246.103.92 --dport 6667 -j DNAT --to-destination :7777 -m comment --comment "bitcoind irc connection"

=== How does the peer finding mechanism work? ===
Bitcoin finds peers primarily by connecting to an IRC server (channel #bitcoin on irc.lfnet.org). If a connection to the IRC server cannot be established (like when connecting through TOR), an in-built node list will be used and the nodes will be queried for more node addresses.

==Mining==
===What is mining?===
Mining is the process of spending computation power to find valid blocks and thus create new Bitcoins.

Technically speaking, mining is the calculation of a [[hash]] of the previous block and a [[nonce]]. If the hash value is found to be less than the current [[difficulty]], a new block is formed and the miner gets 50 newly generated Bitcoins. If the hash is not less than the current difficulty, a new nonce is used, and a new hash is calculated. This is done thousands or millions of times per second by each miner.

===I've been mining for a long time and haven't created any new Bitcoins. What's wrong?===

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- or time-effective method of mining is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]). Since CPU mining is essentially useless, it may be removed from future versions of the Bitcoin software.

===Is mining used for some useful computation?===
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.

===Is it not a waste of energy?===
Spending energy on creating 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.

===Why don't we use calculations that are also useful for some other purpose?===
To provide security for the Bitcoin network, the calculations involved need to have some very specific features. These features are incompatible with leveraging the computation for other purposes.

==Help==
===I'd like to learn more. Where can I get help?===

* Read the [[Introduction|introduction to bitcoin]]
* See the videos, podcasts, and blog posts from the [[Press]]
* Read and post on the [[Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]
* Chat on one of the [[Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works

==See Also==

* [[Man page]]
* [[Introduction]]

[[de:FAQ]]
[[zh-cn:FAQ]]
[[fr:FAQ]]

[[Category:Technical]]
[[Category:Vocabulary]]

Help:FAQ

2011-06-10T22:27:26Z

Garyrowe: Adding denomination detail

Here you will find answers to the most commonly asked questions.

== General ==
=== What are bitcoins? ===
Bitcoins are the unit of currency of the Bitcoin system. A commonly used shorthand for this is “BTC” to refer to a price or amount (eg: “100 BTC”).
A Bitcoin isn't tangible. It is just a number associated with a [[Address|Bitcoin Address]]. See also an [[Introduction|easy intro]] to bitcoin.

=== How can I get Bitcoins? ===

There are five ways to get Bitcoins:

* Buy them on an exchange such as [https://www.mtgox.com/ Mt. Gox] or [http://www.bitcoin-otc.com/ #bitcoin-otc] on FreeNode.
* Accept Bitcoins as payment for goods or services.
* Find a local trader on [http://tradebitcoin.com tradebitcoin] (or somewhere else) and trade with him in cash.
* Create a new [[block]] (currently yields 50 Bitcoins).
* Participate in a [[Pooled mining|mining pool]].

=== Can I buy Bitcoins with Paypal? ===

While it's possible to find an individual who wishes to sell Bitcoin to you via Paypal, (perhaps via [http://www.bitcoin-otc.com/ #bitcoin-otc] ) most major 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 goods. Paypal too often sides with the fraudulent buyer in this case, and so exchangers no longer allow this method of funding.

Buying Bitcoins from individuals with this method is still possible, but requires mutual trust. In this case, Bitcoin seller beware.

=== How are new Bitcoins created? ===

[[File:total_bitcoins_over_time_graph.png|thumb|Number of bitcoins over time, assuming a perfect 10-minute interval.]]
New coins are generated by a network node each time it finds the solution to a certain mathematical problem (i.e. creates a new [[block]]), which is difficult to perform and can demonstrate a [[proof of work]]. The reward for solving a block is [[controlled inflation|automatically adjusted]] so that in the first 4 years of the Bitcoin network, 10,500,000 BTC will be created. The amount is halved each 4 years, so it will be 5,250,000 over years 4-8, 2,625,000 over years 8-12 and so on. Thus the total number of coins will approach 21,000,000 BTC over time.

In addition, built into the network is a system that attempts to allocate new coins in blocks about every 10 minutes, on average, somewhere on the network. As the number of people who attempt to generate these new coins changes, the difficulty of creating new coins changes. This happens in a manner that is agreed upon by the network as a whole, based upon the time taken to generate the previous 2016 blocks. The difficulty is therefore related to the average computing resources devoted to generate these new coins over the time it took to create these previous blocks. The likelihood of somebody "discovering" one of these blocks is based on the computer they are using compared to all of the computers also generating blocks on the network.

=== What's the current total number of Bitcoins in existence? ===

[http://blockexplorer.com/q/totalbc Current count]

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 210,000 blocks, 25 BTC for the next 210,000 blocks, then 12.5 BTC, 6.25 BTC and so on.

=== How divisible are Bitcoins? ===

Technically, a Bitcoin can be divided down to 8 decimals using existing data structures, so 0.00000001 BTC is the smallest amount currently possible. Discussions about and ideas for ways to provide for even smaller quantities of Bitcoins may be created in the future if the need for them ever arises.

=== What do I call the various denominations of Bitcoins? ===

There is a lot of discussion about the naming of these fractions of Bitcoins. The leading candidates are:

* 1 BTC = 1 Bitcoin
* 0.001 BTC = 1 Milli Bitcoin or mbit (pronounced em-bit) or millibit
* 0.000 001 BTC = 1 Micro Bitcoin or ubit (pronounced yu-bit) or microbit
* 0.000 000 001 BTC = 1 Nano Bitcoin or nbit (pronounced en-bit) or nanobit (not currently supported but possible in the future)

The above follows the accepted international SI units for thousandths, millionths and billionths. 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't be the equivalent of 0.01 USD, GBP or EUR). Equally, the inclusion of existing national currency denominations such as "cent", "nickel", "dime", "pence", "pound", "kopek" and so on are to be discouraged. This is a worldwide currency.

One exception is the "satoshi" which is smallest denomination currently possible

* 0.000 000 01 BTC = 1 Satoshi (pronounced sa-toh-shee)

which is so named in honour of Satoshi Nakamoto the pseudonym of the inventor of Bitcoin.

Further discussion on this topic can be found on the forums here:

* [http://forum.bitcoin.org/index.php?topic=14438.msg195287#msg195287 We need names]
* [http://forum.bitcoin.org/index.php?topic=8282.0 What to call 0.001 BTC]

=== How does the halving work when the number gets really small? ===

The reward will go from 0.00000001 BTC to 0. Then no more coins will likely be created.

The calculation is done as a right bitwise shift of a 64-bit signed integer, which means it is divided by 2 and rounded down. The integer is equal to the value in BTC * 100,000,000. This is how all Bitcoin balances/values are stored internally.

Keep in mind that using current rules this will take nearly 100 years before it becomes an issue and Bitcoins may change considerably before that happens.

=== How long will it take to generate all the coins? ===

The last block that will generate coins will be block #6,929,999. This should be generated around year 2140. Then the total number of coins in circulation will remain static at 20,999,999.9769 BTC.

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 20999999.999999999496 BTC.

=== If no more coins are going to be generated, will more blocks be created? ===

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, what will sustain the ability to use bitcoins will be these fees entirely. There will be blocks generated after block #6,929,999, assuming that people are still using Bitcoins at that time.

=== But if no more coins are generated, what happens when Bitcoins are lost? Won't that be a problem? ===

Not at all. 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 when Bitcoins are lost, the remaining Bitcoins will increase in value to compensate. As the value of Bitcoins increase, the number of Bitcoins required to purchase an item '''de'''creases. This is known as a [[Deflationary spiral|deflationary economic model]]. Eventually, if and when it gets to the point where the largest transaction is less than 1BTC, then it's a simple matter of shifting the decimal place to the right a few places, and the system continues.

=== If every transaction is broadcast via the network, does BitCoin scale? ===
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.

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 couple of racks of machines using todays hardware). It's worth noting that the MasterCard network is structured somewhat like BitCoin itself - as a peer to peer broadcast network.

Learn more about [[Scalability]].

=== How does the BitCoin network handle [http://en.wikipedia.org/wiki/CAP_theorem the CAP theorem]? ===

=== Why do I have to wait 10 minutes before I can spend money I received? ===

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.

Blocks (shown as "confirmations" 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'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!

Why ten minutes specifically? It is a tradeoff chosen by Satoshi between propagation time of new blocks in large networks and the amount of work wasted due to chain splits. If that made no sense to you, don't worry. Reading [http://www.bitcoin.org/bitcoin.pdf the technical paper] should make things clearer.

=== Do you have to wait 10 minutes in order to buy or sell things with BitCoin? ===

No, it's reasonable to sell things without waiting for a confirmation as long as the transaction is not of high value.

When people ask this question they are usually thinking about applications like supermarkets or snack machines, as discussed in [http://www.bitcoin.org/smf/index.php?topic=423.msg3819#msg3819 this thread from July 2010]. Zero confirmation transactions still show up in the GUI, but you cannot spend them. You can however reason about the risk involved in assuming you ''will'' be able to spend them in future. In general, selling things that are fairly cheap (like snacks, digital downloads etc) for zero confirmations will not pose a problem if you are running a well connected node.

=== Why does my Bitcoin address keep changing? ===

Whenever the address listed in "Your address" 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 ''Settings -> Your Receiving Addresses''.

==Economy==
=== Where does the value of Bitcoin stem from? What backs up Bitcoin? ===
Bitcoins have value because they are accepted as payment by many. See the [[Trade|list of Bitcoin-accepting sites]].

When we say that a currency is backed up by gold, we mean that there's a promise in place that you can exchange the currency for gold. In a sense, you could say that Bitcoin is "backed up" by the price tags of merchants – a price tag is a promise to exchange goods for a specified amount of currency.

It's a common misconception that Bitcoins gain their value from the cost of electricity required to generate them. Cost doesn'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't make anything valuable. For example, your fingerprints are scarce, but that doesn't mean they have any exchange value.

=== What if someone bought up all the existing Bitcoins? ===
What if somebody bought up all the gold in the world? Well, by attempting to buy it all, the buyer would just drive the prices up until he runs out of money.

Not all Bitcoins are for sale. Just as with gold, no one can buy a Bitcoin that isn't available for sale.

=== Bitcoin's monetary policy causes a deflationary spiral ===
See the article [[Deflationary spiral]].

=== Doesn't Bitcoin unfairly benefit early adopters? ===
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.

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.

=== Is Bitcoin a Ponzi scheme? ===
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.

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 profit from the usefulness of a stable and widely accepted p2p currency.

The fact that early adopters benefit more doesn't alone make anything a ponzi scheme. Apple stocks aren't ponzi even though the early investors got rich.

==Networking==
=== Do I need to configure my firewall to run bitcoin? ===

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. Bitcoin will also try to connect to IRC (tcp port 6667) to meet other nodes to connect to.

If you want to restrict your firewall rules to a few ips and/or don't want to allow IRC connection, you can find stable nodes in the [[Fallback Nodes|fallback nodes list]]. If your provider blocks the common IRC ports, note that lfnet also listens on port 7777. Connecting to this alternate port currently requires either recompiling Bitcoin, or changing routing rules. For example, on Linux you can evade a port 6667 block by doing something like this:

echo 173.246.103.92 irc.lfnet.org >> /etc/hosts
iptables -t nat -A OUTPUT -p tcp --dest 173.246.103.92 --dport 6667 -j DNAT --to-destination :7777 -m comment --comment "bitcoind irc connection"

=== How does the peer finding mechanism work? ===
Bitcoin finds peers primarily by connecting to an IRC server (channel #bitcoin on irc.lfnet.org). If a connection to the IRC server cannot be established (like when connecting through TOR), an in-built node list will be used and the nodes will be queried for more node addresses.

==Mining==
===What is mining?===
Mining is the process of spending computation power to find valid blocks and thus create new Bitcoins.

Technically speaking, mining is the calculation of a [[hash]] of the previous block and a [[nonce]]. If the hash value is found to be less than the current [[difficulty]], a new block is formed and the miner gets 50 newly generated Bitcoins. If the hash is not less than the current difficulty, a new nonce is used, and a new hash is calculated. This is done thousands or millions of times per second by each miner.

===I've been mining for a long time and haven't created any new Bitcoins. What's wrong?===

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- or time-effective method of mining is using a high-end graphics card with special software (see also [[Why a GPU mines faster than a CPU]]). Since CPU mining is essentially useless, it may be removed from future versions of the Bitcoin software.

===Is mining used for some useful computation?===
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.

===Is it not a waste of energy?===
Spending energy on creating 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.

===Why don't we use calculations that are also useful for some other purpose?===
To provide security for the Bitcoin network, the calculations involved need to have some very specific features. These features are incompatible with leveraging the computation for other purposes.

==Help==
===I'd like to learn more. Where can I get help?===

* Read the [[Introduction|introduction to bitcoin]]
* See the videos, podcasts, and blog posts from the [[Press]]
* Read and post on the [[Bitcoin:Community_portal#Bitcoin_Community_Forums|forums]]
* Chat on one of the [[Bitcoin:Community_portal#IRC_Chat|Bitcoin IRC]] channels
* Listen to [http://omegataupodcast.net/2011/03/59-bitcoin-a-digital-decentralized-currency/ this podcast], which goes into the details of how bitcoin works

==See Also==

* [[Man page]]
* [[Introduction]]

[[de:FAQ]]
[[zh-cn:FAQ]]
[[fr:FAQ]]

[[Category:Technical]]
[[Category:Vocabulary]]