A previously little-seen video of the late Hal Finney, a pioneering figure in the world of Bitcoin, has surfaced, shedding light on his groundbreaking work on cryptographic protocols, and giving a rare glimpse of his humanity.
"I want to prove to you that I know a message that hashes to a given hash value using the SHA-1 hash. I don't want to reveal anything about the message to you. It's a zero-knowledge proof, and I've written a program to do this that I'll tell you about," Finney says in the introduction. By selecting SHA-1, a notoriously intricate cryptographic hash function, Finney aimed to create a benchmark for evaluating zero-knowledge proof systems' capabilities. He then highlights the zero-knowledge proof system he employed, based on the work of Cramer and Ivan Damgard, which had been presented at a recent conference. , about the video was the rare glimpse of Finney himself.