Zero knowledge proofs
- Party 1 asserts a statement P to Party 2.
- Party 1 wants to prove P to Party 2 such that:
- Party 2 learns nothing besides what is already stated in the statement P
- Party 2 is unable to prove P to a third party
Three demonstrative examples:
- “I’m holding a red card”
- Show all 26 black cards
- “I know where Waldo is”
- In a cardboard twice as long and twice as wide as the waldo picture, cut a hole the shape of Waldo and display the Waldo through the hole
- (Nit: this actually reveals what Waldo looks like in this picture but is a nice example otherwise)
- “I have a key to the door in this curved tubular cave”
- Have Party 2 close their eyes, randomly enter the cave through left or right, and have Party 2 yell left or right, and then come out that way. Repeat until satisfied