International Association for Cryptologic Research

International Association
for Cryptologic Research


Crowd Verifiable Zero-Knowledge and End-to-end Verifiable Multiparty Computation

Foteini Baldimtsi
Aggelos Kiayias
Thomas Zacharias
Bingsheng Zhang
DOI: 10.1007/978-3-030-64840-4_24
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Presentation: Slides
Abstract: Auditing a secure multiparty computation (MPC) protocol entails the validation of the protocol transcript by a third party that is otherwise untrusted. In this work we introduce the concept of end-to-end verifiable MPC (VMPC), that requires the validation to provide a correctness guarantee even in the setting that all servers, trusted setup primitives and all the client systems utilized by the input-providing users of the MPC protocol are subverted by an adversary. To instantiate VMPC, we introduce a new concept in the setting of zero-knowlegde protocols that we term crowd verifiable zero-knowledge (CVZK). A CVZK protocol enables a prover to convince a set of verifiers about a certain statement, even though each one individually contributes a small amount of entropy for verification and some of them are adversarially controlled. Given CVZK, we present a VMPC protocol that is based on discrete-logarithm related assumptions. At the high level of adversity that VMPC is meant to withstand, it is infeasible to ensure perfect correctness, thus we investigate the classes of functions and verifiability relations that are feasible in our framework, and present a number of possible applications the underlying functions of which can be implemented via VMPC.
Video from ASIACRYPT 2020
  title={Crowd Verifiable Zero-Knowledge and End-to-end Verifiable Multiparty Computation},
  booktitle={Advances in Cryptology - ASIACRYPT 2020},
  author={Foteini Baldimtsi and Aggelos Kiayias and Thomas Zacharias and Bingsheng Zhang},