Bitcoin

Bitcoin
Denominations
Plural	bitcoins
Symbol	₿ (Unicode: U+20BF ₿ BITCOIN SIGN (HTML ₿))[a]
Precision	10−8
Subunits
​1⁄1000	millibitcoin
​1⁄1000000	microbitcoin
​1⁄100000000	satoshi[2]
Development
Original author(s)	Satoshi Nakamoto
White paper	"Bitcoin: A Peer-to-Peer Electronic Cash System"[4]
Implementation(s)	Bitcoin Core
Initial release	0.1.0 / 9 January 2009 (16 years ago) (2009-01-09)
Latest release	22.0 / 13 September 2021 (3 years ago) (2021-09-13)[3]
Code repository	github.com/bitcoin/bitcoin
Development status	Active
Website	bitcoin.org
Ledger
Ledger start	3 January 2009 (16 years ago) (2009-01-03)
Timestamping scheme	Proof-of-work (partial hash inversion)
Hash function	SHA-256 (two rounds)
Issuance schedule	Decentralized (block reward) Initially ₿50 per block, halved every 210,000 blocks[8]
Block reward	₿6.25[b]
Block time	10 minutes
Circulating supply	₿18,830,000[c][5]
Supply limit	₿21,000,000[6][d]
Valuation
Market cap	US$1.149 trillion[e]
↑ The symbol was encoded in Unicode version 10.0 at position U+20BF ₿ BITCOIN SIGN in the Currency Symbols block in June 2017.[1] ↑ May 2020 to approximately 2024, halved approximately every four years ↑ Approximate supply as of 2021-09-30 ↑ The supply will approach, but never reach, ₿21 million. Issuance will permanently halt c. 2140 at ₿20,999,999.9769.[7]: ch. 8  ↑ As of October 22, 2021

Bitcoin ^[a] (₿) is a digital and global money system cryptocurrency. It allows people to send or receive cryptocurrency units across the internet, even to someone they don't know or don't trust. It is the first of its kind technology that allows the transfer of digital scarcity across the internet without needing a third party. Cryptocurrency units can be exchanged without being linked to a real identity. The mathematical field of cryptography is the basis for Bitcoin's security.

Bitcoin was invented by someone using the name Satoshi Nakamoto.^[14] A Bitcoin address, or simply address, is an identifier of 26-35 letters and numbers, beginning with the number 1, 3, or bc1, that represents a possible destination for a bitcoin payment. Addresses can be generated at no cost by any user of Bitcoin. For example, using Bitcoin Core, one can click "New Address" and be assigned an address. It is also possible to get a Bitcoin address using an account at an exchange or online wallet service.

1. ↑ "Unicode 10.0.0". Unicode Consortium. 20 June 2017. Archived from the original on 20 June 2017. Retrieved 20 June 2017.
2. ↑ Mick, Jason (12 June 2011). "Cracking the Bitcoin: Digging Into a $131M USD Virtual Currency". Daily Tech. Archived from the original on 20 January 2013. Retrieved 30 September 2012.
3. ↑ "Bitcoin Core 22.0". Retrieved 14 September 2021.
4. ↑ ^{4.0 4.1} Cite error: The named reference paper was used but no text was provided for refs named (see the help page).
5. ↑ "Bitcoin". 30 September 2021.
6. ↑ Nakamoto; et al. (1 April 2016). "Bitcoin source code - amount constraints". GitHub. Archived from the original on 1 July 2018.
7. ↑ Antonopoulos, Andreas M. (April 2014). Mastering Bitcoin: Unlocking Digital Crypto-Currencies. O'Reilly Media. ISBN 978-1-4493-7404-4.
8. ↑ "Statement of Jennifer Shasky Calvery, Director Financial Crimes Enforcement Network United States Department of the Treasury Before the United States Senate Committee on Banking, Housing, and Urban Affairs Subcommittee on National Security and International Trade and Finance Subcommittee on Economic Policy" (PDF). fincen.gov. Financial Crimes Enforcement Network. 19 November 2013. Archived (PDF) from the original on 9 October 2016. Retrieved 1 June 2014.
9. ↑ Vigna, Paul; Casey, Michael J. (January 2015). The Age of Cryptocurrency: How Bitcoin and Digital Money Are Challenging the Global Economic Order (1 ed.). New York: St. Martin's Press. ISBN 978-1-250-06563-6.
10. ↑ ^{10.0 10.1} "bitcoin". OxfordDictionaries.com. Archived from the original on 2 January 2015. Retrieved 28 December 2014. {{cite web}}: More than one of |archivedate= and |archive-date= specified (help); More than one of |archiveurl= and |archive-url= specified (help)
11. ↑ Bustillos, Maria (2 April 2013). "The Bitcoin Boom". The New Yorker. Condé Nast. Archived from the original on 27 July 2014. Retrieved 22 December 2013. Standards vary, but there seems to be a consensus forming around Bitcoin, capitalized, for the system, the software, and the network it runs on, and bitcoin, lowercase, for the currency itself.
12. ↑ Vigna, Paul (3 March 2014). "BitBeat: Is It Bitcoin, or bitcoin? The Orthography of the Cryptography". WSJ. Archived from the original on 19 April 2014. Retrieved 21 April 2014.
13. ↑ Metcalf, Allan (14 April 2014). "The latest style". Lingua Franca blog. The Chronicle of Higher Education (chronicle.com). Archived from the original on 16 April 2014. Retrieved 19 April 2014.
14. ↑ S., L. (2 November 2015). "Who is Satoshi Nakamoto?". The Economist. The Economist Newspaper Limited. Archived from the original on 21 August 2016. Retrieved 23 September 2016.