Fast Fully Secure Multi-Party Computation over Any Ring with Two-Thirds Honest Majority

Anders Dalskov, Daniel Escudero, Ariel Nof

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations


We introduce a new MPC protocol to securely compute any functionality over an arbitrary black-box finite ring (which may not be commutative), tolerating t < n/3 active corruptions whileguaranteeing output delivery (G.O.D.). Our protocol is based on replicated secret-sharing, whose share size is known to grow exponentially with the number of parties n. However, even though the internal storage and computation in our protocol remains exponential, the communication complexity of our protocol is constant, except for a light constant-round check that is performed at the end before revealing the output. Furthermore, the amortized communication complexity of our protocol is not only constant, but very small: only 1 + t-1 over n < 1 1/3 ring elements per party, per multiplication gate over two rounds of interaction. This improves over the state-of-the art protocol in the same setting by Furukawa and Lindell (CCS 2019), which has a communication complexity of 2 2/3 field elements per party, per multiplication gate and while achieving fairness only. As an alternative, we also describe a variant of our protocol which has only one round of interaction per multiplication gate on average, and amortized communication cost of ≤ 1 1/2 ring elements per party on average for any natural circuit. Motivated by the fact that efficiency of distributed protocols are much more penalized by high communication complexity than local computation/storage, we perform a detailed analysis together with experiments in order to explore how large the number of parties can be, before the storage and computation overhead becomes prohibitive. Our results show that our techniques are viable even for a moderate number of parties (e.g., n>10).

Original languageEnglish
Title of host publicationCCS 2022 - Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security
PublisherAssociation for Computing Machinery
Number of pages14
ISBN (Electronic)9781450394505
StatePublished - 7 Nov 2022
Externally publishedYes
Event28th ACM SIGSAC Conference on Computer and Communications Security, CCS 2022 - Los Angeles, United States
Duration: 7 Nov 202211 Nov 2022

Publication series

NameProceedings of the ACM Conference on Computer and Communications Security
ISSN (Print)1543-7221


Conference28th ACM SIGSAC Conference on Computer and Communications Security, CCS 2022
Country/TerritoryUnited States
CityLos Angeles

Bibliographical note

Funding Information:
A. Nof supported by ERC Project NTSC (742754). This paper was prepared in part for information purposes by the Artificial Intelligence Research group of JPMorgan Chase & Co and its affiliates (“JP Morgan”), and is not a product of the Research Department of JP Morgan. JP Morgan makes no representation and warranty whatsoever and disclaims all liability, for the completeness, accuracy or reliability of the information contained herein. This document is not intended as investment research or investment advice, or a recommendation, offer or solicitation for the purchase or sale of any security, financial instrument, financial product or service, or to be used in any way for evaluating the merits of participating in any transaction, and shall not constitute a solicitation under any jurisdiction or to any person, if such solicitation under such jurisdiction or to such person would be unlawful. 2021 JP Morgan Chase & Co. All rights reserved.

Publisher Copyright:
© 2022 ACM.


  • honest majority
  • multiparty computation
  • robust computation

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