John’s thread on zero-knowledge proofs
One idea that comes up a lot in certain technology circles, especially cryptocurrency, is the idea of a “zero-knowledge” proof, or ZKP. Here’s a quick analogy that might be helpful to explain how a ZKP works. Let’s say there is a wall of 1,000 locked safes. I want to verify that you own each safe. You could do that by unlocking all the safes, but that would reveal the combination to me, and you don't want me to know the secret. We seem to be at an impasse. One way out of this dilemma is for me to leave the room. I tell you, “I’m going to leave and come back in 1 hour. Please open all the safes.” If I come back and the safes are open, it's probably because you knew the combinations to each safe. You never had to tell me the secret (the safe combination), and I don’t have to know what the secret is to be satisfied that you know it. That’s the “zero knowledge” part.
