Bitcoin is a cryptocurrency, a digital asset designed to work as a medium of exchange that uses cryptography to control its creation and management, rather than relying on central authorities.[1] The presumed pseudonymous Satoshi Nakamoto integrated many existing ideas from the cypherpunk community when creating bitcoin. Over the course of bitcoin's history, it has undergone rapid growth to become a significant currency both on and offline – from the mid 2010s onward, some businesses on a global scale began accepting bitcoins in addition to fiat currencies.
Prior to the release of bitcoin there were a number of digital cash technologies starting with the issuer based ecash protocols of David Chaum[3] and Stefan Brands. Adam Back developed hashcash, a proof-of-work scheme for spam control. The first proposals for distributed digital scarcity based cryptocurrencies were Wei Dai's b-money[4] and Nick Szabo's bit gold.[5][6] Hal Finney developed reusable proof of work (RPOW) using hashcash as its proof of work algorithm.[7]
Pre-history
In the bit gold proposal which proposed a collectible market based mechanism for inflation control, Nick Szabo also investigated some additional enabling aspects including a Byzantine fault-tolerant asset registry to store and transfer the chained proof-of-work solutions.[6]
There has been much speculation as to the identity of Satoshi Nakamoto with suspects including Dai, Szabo, and Finney – and accompanying denials.[8][9] The possibility that Satoshi Nakamoto was a computer collective in the European financial sector has also been discussed.[10]
