Bitcoin
Bitcoin (abbreviation: BTC or XBT; sign: ₿) is the first decentralized cryptocurrency. Nodes in the peer-to-peer bitcoin network verify transactions through cryptography and record them in a public distributed ledger, called a blockchain, without central oversight.
Logo of Bitcoin | |
| Denominations | |
|---|---|
| Plural | Bitcoins |
| Symbol | ₿ (Unicode: U+20BF ₿ BITCOIN SIGN) |
| Code | BTC, XBT |
| Precision | 10−8 |
| Subunits | |
| 1⁄1000 | Millibitcoin |
| 1⁄1000000 | Microbitcoin |
| 1⁄100000000 | Satoshi |
| Development | |
| Original author(s) | Satoshi Nakamoto |
| White paper | "Bitcoin: A Peer-to-Peer Electronic Cash System" |
| Implementation(s) | Bitcoin Core |
| Initial release | 0.1.0 / 9 January 2009 |
| Latest release | 25.1 / 19 October 2023 |
| Code repository | github |
| Development status | Active |
| Written in | C++ |
| Source model | Free and open-source software |
| License | MIT License |
| Ledger | |
| Ledger start | 3 January 2009 |
| 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 |
| Block reward | ₿6.25 (as of 2023) |
| Block time | 10 minutes |
| Circulating supply | ₿19,591,231 (as of 6 January 2024) |
| Supply limit | ₿21,000,000 |
| Valuation | |
| Exchange rate | Floating |
| Demographics | |
| Official user(s) | El Salvador |
Consensus between nodes is achieved using a computationally intensive system based on proof-of-work, called mining, that requires increasing quantities of electricity.
Based on a free market ideology, bitcoin was invented in 2008 by Satoshi Nakamoto, an unknown person. Use of bitcoin as a currency began in 2009, with the release of its open-source implementation.: ch. 1 In 2021, El Salvador adopted it as legal tender. Bitcoin is currently used more as a store of value and less as a medium of exchange or unit of account. It is mostly seen as an investment and has been described by many scholars as an economic bubble. As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries as of 2021.