Zero-Knowledge Proof

a proof that an entity has knowledge of something that does not give away any additional information

see proof, cryptography

example colorblind verifier

a prover wants to show a verifier that they know the color of two balls without revealing either color. note that the verifier cannot see the color of either ball as they are colorblind

1. the verifier hides both balls behind their back and may or may not switch the balls around
2. the verifier reveals the balls and asks the prover to say whether the balls were switched or not

the process above is repeated some number of times to reduce the probability of "lucky guesses" from an untrustworthy prover

this algorithm proves with high probability that the prover knows the color of both balls without revealing either color