25-year old video shows Bitcoin pioneer Hal Finney talking zero-knowledge proofs
Finney, who received the first bitcoin transaction from Satoshi Nakamoto, was recorded presenting code at the Crypto ‘98 conference

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A newly-unearthed video shows the Bitcoin pioneer Hal Finney giving a talk on zero-knowledge proofs at the Crypto ‘98 conference.
In the video, Finney talks about performing a zero-knowledge proof on a SHA-1 hash, demonstrating the existence of a cryptographically scrambled message without disclosing any details about the message. At the time of Finney’s talk, zero-knowledge proofs were known to be theoretically possible, but were generally viewed as inefficient or unfeasible.
“I wanted to find out just how inefficient or impractical they really are,” Finney says in the video before proposing a zero-knowledge proof system.
Much of Finney’s life was marked by challenging the boundaries of what was deemed possible. In 2009, the cypherpunk was the first bitcoin recipient, receiving ten bitcoin from the cryptocurrency’s pseudonymous founder Satoshi Nakamoto. The same year, Finney was diagnosed with ALS. Just shortly after, he wrote in a blog post: “[M]y dream is to contribute to open source software projects even from within an immobile body. That will be a life very much worth living.” Finney died in 2014 and is cryopreserved in Arizona.
The subject of Finney’s 25-year old talk remains vexing today. Ethereum layer-2s are locked in an arms race building zero-knowledge proofs to scale the ecosystem. However, the efficacy of this technology is yet to be established. Implementing zero-knowledge proofs can be prohibitively costly or compromise security, rendering them inefficient and impractical.
In Finney-ian fashion, though, crypto developers are still chipping away at a solution.
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