Zero-Knowledge Proof and Authentication Protocols

Zero-knowledge proofs are a cryptographic technique that allows one entity, the prover, to convince another, the verifier, of the truth of a statement without revealing any information other than that the statement is true. Neither the verifier nor any observer of the interaction between the two parties will have any information they did not have before. The zero-knowledge property provides some desirable characteristics for an authentication protocol. Since a zero-knowledge authentication process provides no new information to an eavesdropper, the protocol is immune to replay attacks. Further, since the verifier never learns anything about the user’s credentials, even an attacker that completely compromises the server still can’t get information that would allow them to impersonate a user.