Nick Szabo
Nick Szabo is a computer scientist, legal scholar and cryptographer known for his research in digital contracts and digital currency. He graduated from the University of Washington in 1989 with a degree in computer science.
The phrase and concept of "smart contracts" was developed by Szabo with the goal of bringing what he calls the "highly evolved" practices of contract law and practice to the design of electronic commerce protocols between strangers on the Internet. Smart contracts are a major feature of cryptocurrencies and the E programming language.
Szabo influentially argued that a minimum granularity of micropayments is set by mental transaction costs.
Bit gold
In 1998, Szabo designed a mechanism for a decentralized digital currency he called “bit gold”. Bit gold failed to garner widespread support, but has been called ‘a direct precursor to the Bitcoin architecture.’
In Szabo’s bit gold scheme, a participant would dedicate computer power to solving cryptographic puzzles. In a bit gold network, solved puzzles would be sent to the Byzantine fault-tolerant public registry and assigned to the public key of the solver. Each solution would become part of the next challenge, creating a growing chain of new property. This aspect of the system provided a way for the network to verify and time-stamp new coins, because unless a majority of the parties agreed to accept new solutions, they couldn’t start on the next puzzle.