Critical Rounds in Multi-Round Proofs: Proof of Partial Knowledge and Trapdoor Commitments (original) (raw)

Paper 2024/1766

Critical Rounds in Multi-Round Proofs: Proof of Partial Knowledge and Trapdoor Commitments

David Balbás, ETH Zurich, Switzerland

Dung Bui, Sorbonne Université, CNRS, LIP6, Paris, France

Miyako Ohkubo, NICT

Zehua Shang, Kyoto University

Akira Takahashi, J.P. Morgan AI Research & AlgoCRYPT Center of Excellence

Mehdi Tibouchi, NTT Social Informatics Laboratories

Abstract

Zero-knowledge simulators, initially developed for proving the security of proof systems, turned out to be also useful in constructing advanced protocols from simple three-move interactive proofs. However, in the context of multi-round public-coin protocols, the interfaces of these auxiliary algorithms become more complex, introducing a range of technical challenges that hinder the generalization of these constructions. We introduce a framework to enhance the usability of zero-knowledge simulators in multi-round argument systems for protocol designs. Critical-round zero-knowledge relies on the ability to perform complete zero-knowledge simulations by knowing the challenge of just one specific round in advance. We show that these notions are satisfied by diverse protocols based on MPC-in-the-Head, interactive oracle proofs, and split-and-fold arguments. We demonstrate the usefulness of the critical round framework by constructing proofs of partial knowledge (Cramer, Damgård, and Schoenmakers, CRYPTO’94) and trapdoor commitments (Damgård, CRYPTO’89) from critical-round multi-round proofs.

BibTeX

@misc{cryptoeprint:2024/1766, author = {Masayuki Abe and David Balbás and Dung Bui and Miyako Ohkubo and Zehua Shang and Akira Takahashi and Mehdi Tibouchi}, title = {Critical Rounds in Multi-Round Proofs: Proof of Partial Knowledge and Trapdoor Commitments}, howpublished = {Cryptology {ePrint} Archive, Paper 2024/1766}, year = {2024}, url = {https://eprint.iacr.org/2024/1766} }