Perfect Zero-Knowledge in Constant Rounds

Quadratic residuosity and graph isomorphism are classic problems and the canonical examples of zero-knowledge languages. However, despite much research e ort, all previous zeroknowledge proofs for them required either cryptography (and thus unproven assumptions) or an unbounded number of rounds of message exchange. For both (and similar) languages, we exhibit zero-knowledge proofs that require 5 rounds and no unproven assumptions. Our solution is essentially optimal, in this setting, due to a recent lowerbound argument of Goldreich and Krawzcyk.

• Type: Conference
• Year: 1990
• Where: STOC
• Authors: Mihir Bellare, Silvio Micali, Rafail Ostrovsky
• Keywords: Algorithms, STOC 1990, Unproven Assumptions, Zero-knowledge Languages, Zero-knowledge Proofs