Resettable Zero Knowledge in the Bare Public-Key Model under Standard Assumption

TL;DR

This paper presents a protocol for constant-round resettable zero-knowledge arguments with concurrent soundness for NP in the bare public-key model, relying only on collision-resistant hash functions, resolving an open problem.

Contribution

It introduces the first such protocol in the BPK model that does not require sub-exponential hardness assumptions.

Findings

Achieves constant-round resettable zero-knowledge with concurrent soundness for NP.

Relies solely on collision-resistant hash functions, no sub-exponential hardness needed.

Addresses an open problem in cryptographic protocol design.

Abstract

In this paper we resolve an open problem regarding resettable zero knowledge in the bare public-key (BPK for short) model: Does there exist constant round resettable zero knowledge argument with concurrent soundness for $\mathcal{NP}$ in BPK model without assuming \emph{sub-exponential hardness}? We give a positive answer to this question by presenting such a protocol for any language in $\mathcal{NP}$ in the bare public-key model assuming only collision-resistant hash functions against \emph{polynomial-time} adversaries.