Title
Round-Optimal Secure Multi-Party Computation
Abstract
Secure multi-party computation (MPC) is a central cryptographic task that allows a set of mutually distrustful parties to jointly compute some function of their private inputs where security should hold in the presence of an active (i.e. malicious) adversary that can corrupt any number of parties. Despite extensive research, the precise round complexity of this "standard-bearer" cryptographic primitive, under polynomial-time hardness assumptions, is unknown. Recently, Garg, Mukherjee, Pandey and Polychroniadou, in Eurocrypt 2016 demonstrated that the round complexity of any MPC protocol relying on black-box proofs of security in the plain model must be at least four. Following this work, independently Ananth, Choudhuri and Jain, CRYPTO 2017 and Brakerski, Halevi, and Polychroniadou, TCC 2017 made progress towards solving this question and constructed four-round protocols based on the DDH and LWE assumptions, respectively, albeit with super-polynomial hardness. More recently, Ciampi, Ostrovsky, Siniscalchi and Visconti in TCC 2017 closed the gap for two-party protocols by constructing a four-round protocol from polynomial-time assumptions, concretely, trapdoor permutations. In another work, Ciampi, Ostrovsky, Siniscalchi and Visconti TCC 2017 showed how to design a four-round multi-party protocol for the specific case of multi-party coin-tossing based on one-way functions. In this work, we resolve this question by designing a four-round actively secure multi-party (two or more parties) protocol for general functionalities under standard polynomial-time hardness assumptions with a black-box proof of security, specifically, under the assumptions LWE, DDH, QR and DCR.
Year
DOI
Venue
2021
10.1007/s00145-021-09382-3
JOURNAL OF CRYPTOLOGY
Keywords
DocType
Volume
Secure multi-party computation, Garbled circuits, Round complexity, Additive errors
Journal
34
Issue
ISSN
Citations 
3
0933-2790
1
PageRank 
References 
Authors
0.35
0
4
Name
Order
Citations
PageRank
Shai Halevi17203442.70
Carmit Hazay258635.54
Antigoni Polychroniadou312.38
Muthuramakrishnan Venkitasubramaniam4144273.06