Statistical Concurrent Non-malleable Zero-Knowledge from One-Way Functions

Concurrent non-malleable zero-knowledge (CNMZK) protocols are zero-knowledge protocols that are secure even against adversaries that interact with multiple provers and verifiers simultaneously. Recently, the first statistical CNMZK argument forNP was constructed under the DDH assumption (Orlandi el al., TCC’14). In this paper, we construct a statistical CNMZK argument forNP assuming only the existence of one-way functions. The security is proven via black-box simulation, and the round complexity is poly(n). Under the existence of collision-resistant hash functions, the round complexity can be reduced to ω(log n), which is known to be essentially optimal for black-box concurrent zeroknowledge protocols. This paper is the full version of the paper that appears in the proceedings of CRYPTO 2015.