Bitcoin
Created by Satoshi Nakamoto
Bitcoin is the first decentralized cryptocurrency, launched in 2009, that enables peer-to-peer digital payments secured by a proof-of-work blockchain without requiring a bank or central authority.
Definition
Bitcoin is the first decentralized cryptocurrency, launched in 2009, that enables peer-to-peer digital payments secured by a proof-of-work blockchain without requiring a bank or central authority.
Overview
Bitcoin was introduced in a 2008 white paper published under the pseudonym Satoshi Nakamoto and launched in January 2009, proposing a purely peer-to-peer version of electronic cash. Its core innovation was combining a blockchain ledger with a proof-of-work consensus algorithm, which lets a network of mutually distrusting computers agree on transaction history without a central authority, solving the long-standing double-spend problem for digital money. Miners compete to solve a computationally expensive puzzle to add the next block, and are rewarded with newly issued bitcoin plus transaction fees. Bitcoin's total supply is capped by protocol rules at 21 million coins, with the issuance rate halving roughly every four years, giving it a predictable, disinflationary monetary policy that supporters often compare to a form of digital gold. As the original cryptocurrency, Bitcoin remains the largest by market value and is generally treated as a store-of-value asset and payment network, in contrast to more programmable platforms like Ethereum that support smart contracts.
Specification
- Fully decentralized network with no central issuing authority
- Proof-of-work consensus securing the ledger through mining
- Fixed maximum supply of 21 million coins
- Issuance rate halves approximately every four years
- Transactions are irreversible once sufficiently confirmed
- Open-source protocol maintained by a distributed developer community
- Widely used as a store-of-value and speculative investment asset
Use Cases
History
Bitcoin is the first decentralized digital currency. It was introduced in a white paper titled "Bitcoin: A Peer-to-Peer Electronic Cash System," posted to a cryptography mailing list on October 31, 2008 under the pseudonym Satoshi Nakamoto, whose real identity remains unknown. The network went live on January 3, 2009, when Nakamoto mined the first block — the "genesis block" — which carried a 50-bitcoin reward and embedded the newspaper headline "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks," both timestamping the launch and signaling its motivation. Bitcoin's design combines a public, append-only blockchain, proof-of-work mining, and a capped supply to enable value transfer between parties without a trusted central intermediary, and it launched the entire cryptocurrency field.
Sources
- bitcoin.org — original Bitcoin white paper (Satoshi Nakamoto, 2008) · as of 2026-07-17
- River — "Who is Satoshi Nakamoto?" (Bitcoin history) · as of 2026-07-17