In 2004, Hal Finney developed the first currency based on reusable proof-of-work. The first proposals for distributed digital scarcity-based cryptocurrencies came from cypherpunks Wei Dai (b-money) and Nick Szabo ( bit gold) in 1998. The concept was independently rediscovered by Adam Back who developed Hashcash, a proof-of-work scheme for spam control in 1997. The idea that solutions to computational puzzles could have some value was first proposed by cryptographers Cynthia Dwork and Moni Naor in 1992. Main article: History of bitcoin Backgroundīefore bitcoin, several digital cash technologies were released, starting with David Chaum's ecash in the 1980s.

Its proof-of-work algorithm for bitcoin mining is computationally difficult and requires increasing quantities of electricity, so that, as of 2022, bitcoin is estimated to be responsible for 0.2% of world greenhouse gas emissions.

The environmental effects of bitcoin are also substantial. Īs bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by 51 countries as of 2021. It is mostly seen as an investment and has been described by many scholars as an economic bubble. Bitcoin is currently used less as a medium of exchange and more as a store of value. 1 In 2021, El Salvador adopted it as legal tender. Use of bitcoin as a currency began in 2009, with the release of its open-source implementation. Based on a free market ideology, bitcoin was invented in 2008 by Satoshi Nakamoto, an unknown person.

Nodes in the bitcoin network verify transactions through cryptography and record them in a public distributed ledger called a blockchain. Without proper rendering support, you may see question marks, boxes, or other symbols.īitcoin ( abbreviation: BTC or XBT sign: ₿) is the first decentralized cryptocurrency. This article contains special characters. Initially ₿50 per block, halved every 210,000 blocks

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