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).
|Title of host publication||CCS 2022 - Proceedings of the 2022 ACM SIGSAC Conference on Computer and Communications Security|
|Publisher||Association for Computing Machinery|
|Number of pages||14|
|State||Published - 7 Nov 2022|
|Event||28th ACM SIGSAC Conference on Computer and Communications Security, CCS 2022 - Los Angeles, United States|
Duration: 7 Nov 2022 → 11 Nov 2022
|Name||Proceedings of the ACM Conference on Computer and Communications Security|
|Conference||28th ACM SIGSAC Conference on Computer and Communications Security, CCS 2022|
|Period||7/11/22 → 11/11/22|
Bibliographical noteFunding 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.
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- honest majority
- multiparty computation
- robust computation