Efficient constant-round mpc with identifiable abort and public verifiability

Research output: Contribution to book/anthology/report/proceedingArticle in proceedingsResearchpeer-review

Recent years have seen a tremendous growth in the interest in secure multiparty computation (MPC) and its applications. While much progress has been made concerning its efficiency, many current, state-of-the-art protocols are vulnerable to Denial of Service attacks, where a cheating party may prevent the honest parties from learning the output of the computation, whilst remaining anonymous. The security model of identifiable abort aims to prevent these attacks, by allowing honest parties to agree upon the identity of a cheating party, who can then be excluded in the future. Several existing MPC protocols offer security with identifiable abort against a dishonest majority of corrupted parties. However, all of these protocols have a round complexity that scales linearly with the depth of the circuit (and are therefore unsuitable for use in high latency networks) or use cryptographic primitives or techniques that have a high computational overhead. In this work, we present the first efficient MPC protocols with identifiable abort in the dishonest majority setting, which run in a constant number of rounds and make only black-box use of cryptographic primitives. Our main construction is built from highly efficient primitives in a careful way to achieve identifiability at a low cost. In particular, we avoid the use of public-key operations outside of a setup phase, incurring a relatively low overhead on top of the fastest currently known constant-round MPC protocols based on garbled circuits. Our construction also avoids the use of adaptively secure primitives and heavy zero-knowledge machinery, which was inherent in previous works. In addition, we show how to upgrade our protocol to achieve public verifiability using a public bulletin board, allowing any external party to verify correctness of the computation or identify a cheating party.

Original languageEnglish
Title of host publicationAdvances in Cryptology - CRYPTO 2020
EditorsDaniele Micciancio, Thomas Ristenpart
Number of pages31
Place of publicationCham
PublisherSpringer
Publication year2020
Pages562-592
ISBN (print)9783030568795
ISBN (Electronic)978-3-030-56880-1
DOIs
Publication statusPublished - 2020
Event40th Annual International Cryptology Conference, CRYPTO 2020 - Santa Barbara, United States
Duration: 17 Aug 202021 Aug 2020

Conference

Conference40th Annual International Cryptology Conference, CRYPTO 2020
LandUnited States
BySanta Barbara
Periode17/08/202021/08/2020
SeriesLecture Notes in Computer Science
Volume12171
ISSN0302-9743

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