Cryptology ePrint Archive: Report 2018/613

One-Message Zero Knowledge and Non-Malleable Commitments

Nir Bitansky and Huijia Lin

Abstract: We introduce a new notion of one-message zero-knowledge (1ZK) arguments that satisfy a weak soundness guarantee the number of false statements that a polynomial-time non-uniform adversary can convince the verifier to accept is not much larger than the size of its non-uniform advice. The zero-knowledge guarantee is given by a simulator that runs in (mildly) super-polynomial time.

We construct such 1ZK arguments based on the notion of multi-collision-resistant keyless hash functions, recently introduced by Bitansky, Kalai, and Paneth (STOC 2018). Relying on the constructed 1ZK arguments, subexponentially-secure time-lock puzzles, and other standard assumptions, we construct one-message fully-concurrent non-malleable commitments. This is the first construction that is based on assumptions that do not already incorporate non-malleability, as well as the first based on (subexponentially) falsifiable assumptions.

Category / Keywords: foundations / Zero-Knowledge, Non-Malleable-Commitments, Concurrency, Collision-Resistance

Date: received 16 Jun 2018, last revised 17 Jun 2018

Contact author: nbitansky at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20180622:144630 (All versions of this report)

Short URL: ia.cr/2018/613


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