On constant-round zero-knowledge proofs of knowledge for NP-relations

HongDa Li, Haixia Xu, Bao Li, Dengguo Feng

Abstract: This paper considers the existence of constant-round zero-knowledge proofs of knowledge for NP under standard assumptions. By introducing a new interactive proof model, we construct a 3-round zero-knowledge proof of knowledge system for the NP-relation under the assumption that factoring is intractable. Our construction not only shows the existence of constant-round zero-knowledge proofs of knowledge, but also gives a positive answer to the open problem of the existence of 3-round zero-knowledge proofs for NP.