Bitcoin is a cryptocurrency and worldwide payment system.[9]:3 It is the first decentralized[a] digital currency.[9]:1[10] Its conception is peer-to-peer and transactions take place between users directly, without an intermediary.[9]:4 These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a blockchain. Bitcoin was invented by an unknown person or group of people under the name Satoshi Nakamoto[11] and released as open-source software in 2009.[12]
Bitcoin
Prevailing bitcoin logo
Prevailing bitcoin logo
Denominations
Plural
bitcoins
Symbol
₿[a]
Ticker symbol
BTC, XBT[b]
Subunits
1⁄1000
millibitcoin[1]
1⁄1000000
bit[3][better source needed]
1⁄100000000
satoshi[4]
Coins
Unspent outputs of transactions (in multiples of a satoshi)[5]:ch. 5
Development
Original author(s)
Satoshi Nakamoto
White paper
Bitcoin: A Peer-to-Peer Electronic Cash System[6]
Implementation(s)
Bitcoin Core
Initial release
0.1.0 / 9 January 2009 (9 years ago)
Latest release
0.15.1 / 11 November 2017 (3 months ago)
Website
bitcoin.org
Ledger
Ledger start
3 January 2009 (9 years ago)
Timestamping scheme
Proof-of-work (partial hash inversion)
Hash function
SHA-256
Issuance
Decentralized, block reward[7][8]
Block reward
₿12.5[c]
Block time
10 minutes
Block explorer
blockchain.info
Circulating supply
₿16,858,762 (as of 11 February 2018)
Supply limit
₿21,000,000
Valuation
Exchange rate
Increase US$10,710 (as of 17 February 2018)
Market cap
Increase US$181 billion (as of 17 February 2018)
