International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Round-optimal Black-box Commit-and-prove with Succinct Communication

Susumu Kiyoshima , NTT Research
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Conference: CRYPTO 2020
Abstract: We give a four-round black-box construction of a commit-and-prove protocol with succinct communication. Our construction is WI and has constant soundness error, and it can be upgraded into a one that is ZK and has negligible soundness error by relying on a round-preserving transformation of Khurana et al. (TCC 2018). Our construction is obtained by combining the MPC-in-the-head technique of Ishai et al. (SICOMP 2009) with the two-round succinct argument of Kalai et al. (STOC 2014), and the main technical novelty lies in the analysis of the soundness---we show that, although the succinct argument of Kalai et al. does not necessarily provide soundness for NP statements, it can be used in the MPC-in-the-head technique for proving the consistency of committed MPC views. Our construction is based on sub-exponentially hard collision-resistant hash functions, two-round PIRs, and two-round OTs.
Video from CRYPTO 2020
  title={Round-optimal Black-box Commit-and-prove with Succinct Communication},
  author={Susumu Kiyoshima},