## Cryptology ePrint Archive: Report 2017/189

Global-Scale Secure Multiparty Computation

Xiao Wang and Samuel Ranellucci and Jonathan Katz

Abstract: We propose a new, constant-round protocol for multi-party computation of boolean circuits that is secure against an arbitrary number of malicious corruptions. At a high level, we extend and generalize recent work of Wang et al. in the two-party setting and design an efficient preprocessing phase that allows the parties to generate authenticated information; we then show how to use this information to distributively construct a single authenticated'' garbled circuit that is evaluated by one party.

Our resulting protocol improves upon the state-of-the-art both asymptotically and concretely. We validate these claims via several experiments demonstrating both the efficiency and scalability of our protocol:

- Efficiency: For three-party computation over a LAN, our protocol requires only 95 ms to evaluate AES. This is roughly a 700$\times$ improvement over the best prior work, and only 2.5$\times$ slower than the best known result in the two-party setting. In general, for $n$ parties our protocol improves upon prior work (which was never implemented) by a factor of more than $230n$, e.g., an improvement of 3 orders of magnitude for 5-party computation.

- Scalability: We successfully executed our protocol with a large number of parties located all over the world, computing (for example) AES with 128 parties across 5 continents in under 3 minutes. Our work represents the largest-scale demonstration of secure computation to date.

Category / Keywords: cryptographic protocols / multi-party computation, secure computation, garbled circuits

Date: received 24 Feb 2017, last revised 22 May 2017

Contact author: wangxiao at cs umd edu

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2017/189

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