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. Prior to the release of bitcoin there were a number of digital cash technologies starting with the issuer based ecash protocols of Teraexchange bitcoin wiki Chaum and Stefan Brands. 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. The possibility that Satoshi Nakamoto was a computer collective in the European financial sector has also been discussed.
On 18 August 2008, the domain name bitcoin. 2009 Chancellor on brink of second bailout for banks. The text refers to a headline in The Times published on 3 January 2009. This note has been interpreted as both a timestamp of the genesis date and a derisive comment on the instability caused by fractional-reserve banking. The first open source bitcoin client was released on 9 January 2009.