Blockchain

Blockchain definition: A decentralized, distributed ledger technology that records transactions across multiple computers, preventing retroactive alteration without changing all subsequent blocks. This enables participants to verify and audit transactions without a central authority.

Blockchain technology was first proposed in 1991 by researchers Stuart Haber and W. Scott Stornetta to create tamper-proof document timestamps. It remained largely unused until Satoshi Nakamoto adapted it in 2008 to develop Bitcoin, a peer-to-peer digital cash system.

Blockchains are inherently secure, functioning as distributed computing systems with high Byzantine fault tolerance. This makes them suitable for recording events, medical records, identity management, transaction processing, and tracking provenance.

A blockchain consists of a series of blocks containing data specific to the blockchain type. For instance, the Bitcoin blockchain records transaction details like sender, receiver, and amount. Each block has a unique hash, similar to a fingerprint, that identifies its contents.

Bitcoin is the world’s most recognized blockchain, launched in 2009. It offers lower transaction fees than traditional online payments and operates under a decentralized authority, unlike government-backed currencies.

There are different types of blockchains: public, private, and consortium. Public blockchains like Bitcoin and Ethereum are open to anyone, while private blockchains like Hyperledger and R3 require permission to join.

Blockchain technology has disruptive potential across industries by enhancing democratic processes, security, transparency, and efficiency. Applications range from fund transfers and trade settlements to voting and other financial, political, and social areas.