Cryptology ePrint Archive: Report 2021/500

Order-C Secure Multiparty Computation for Highly Repetitive Circuits

Gabrielle Beck and Aarushi Goel and Abhishek Jain and Gabriel Kaptchuk

Abstract: Running secure multiparty computation (MPC) protocols with hundreds or thousands of players would allow leveraging large volunteer networks (such as blockchains and Tor) and help justify honest majority assumptions. However, most existing protocols have at least a linear (multiplicative)dependence on the number of players, making scaling difficult. Known protocols with asymptotic efficiency independent of the number of parties (excluding additive factors) require expensive circuit transformations that induce large overheads.

We observe that the circuits used in many important applications of MPC such as training algorithms used to create machine learning models have a highly repetitive structure. We formalize this class of circuits and propose an MPC protocol that achieves O(|C|) total complexity for this class. We implement our protocol and show that it is practical and outperforms O(n|C|) protocols for modest numbers of players.

Category / Keywords: cryptographic protocols / Secure multiparty computation

Original Publication (with major differences): IACR-EUROCRYPT-2021

Date: received 18 Apr 2021, last revised 3 Nov 2021

Contact author: gbeck at cs jhu edu, aarushig at cs jhu edu, abhishek at cs jhu edu, kaptchuk at bu edu

Available format(s): PDF | BibTeX Citation

Version: 20211103:201609 (All versions of this report)

Short URL: ia.cr/2021/500