Resettable zero knowledge with concurrent soundness in the bare public-key model understandard assumption

Abstract

In this paper we present the first constant round resettable zero knowledge arguments with concurrent soundness for in the bare public-key (BPK for short) model assuming only collision-resistant hash functions against polynomial-time adversaries. This resolves the problem whether there exist such protocols for in BPK model without assuming sub-exponential hardness. In our protocol, the resettable zero knowledge is demonstrated via a black-box simulator, while the concurrent soundness is proved by using the malicious prover strategy in non-black-box manner. © 2008 Springer-Verlag Berlin Heidelberg.