Nick Szabo

In the mid-1990s Szabo described smart contracts as contract terms embedded in code and hardware, with the vending machine as his stock example: insert coin, receive soda, no lawyer required. He had worked for David Chaum's DigiCash and watched up close how a digital currency with a central issuer could fall over.

Bit gold, sketched in 1998, chained proofs of work together with timestamps to create a scarce digital asset with no issuer. The resemblance to Bitcoin is close enough that Szabo has often been named as Satoshi Nakamoto. He has denied it, and the evidence consists mostly of stylometry and wishful thinking.