Bitcoin is the first cryptocurrency, a form of money that uses cryptography to control its creation and management, rather than relying on central authorities. However, not all of the technologies and concepts that make up Bitcoin are new; the presumed pseudonym Satoshi Nakamoto (the creator of Bitcoin) integrated many existing ideas from the cypherpunk community when creating Bitcoin.
Prior to the release of Bitcoin there were a number of precursor eCash technologies starting with the issuer based eCash protocols of David Chaum and Stefan Brands, and moving on to distributed digital scarcity based eCash protocols starting from Adam Back’s hashcash, Wei Dai’s b-money, Nick Szabo’s bit-gold and Hal Finney’s RPOW which build on hashcash.
Independently and at around the same time Wei Dai proposed b-money and Nick Szabo proposed bit-gold. Subsequently Hal Finney implemented and deployed RPOW a reusable form of hashcash based on IBM secure TPM hardware and remote attestation (centralized but with no issuer inflation risk).
Since the initial bit-gold proposal which proposed a collectible market based mechanism for inflation control Nick Szabo also investigated some additional enabling aspects for decentralized asset registers including Byzantine network issues.
There has been much speculation as to the identity of Satoshi Nakamoto with suspects including Wei Dai, Hal Finney and accompanying denials. The possibility that Satoshi Nakamoto was a computer collective in the European financial sector has also been bruited.