Z

Zero Knowledge Proof

A protocol with the aim to convince the recipient that the sender has a certain piece of information and at the same time keep all of the secret (therefore "zero knowledge"). If the sender has the information, he can always send the correct bit. Otherwise he can send the correct bit only with a 50% chance. By iteration of this call-and-response game the recipient can rule out error probabilities as small as he wants. (This simplified explanation is not the general mathematical definition of a Zero Knowledge Proof). Zero-Knowledge protocols allow identification, key exchange and other basic cryptographic operations to be implemented without leaking any secret information during the conversation. Thus Zero-Knowledge protocols can provide the functionalities of public-key protocols.