Dishonest Majority Constant-Round MPC with Linear Communication from DDH

Vipul Goyal, Junru Li, Ankit Kumar Misra, Rafail Ostrovsky, Yifan Song, Chenkai Weng

Abstract: In this work, we study constant round multiparty computation (MPC) for Boolean circuits against a fully malicious adversary who may control up to \(n-1\) out of n parties. Without relying on fully homomorphic encryption (FHE), the best-known results in this setting are achieved by Wang et al. (CCS 2017) and Hazay et al. (ASIACRYPT 2017) based on garbled circuits, which require a quadratic communication in the number of parties \(O(|C|\cdot n^2)\). In contrast, for non-constant round MPC, the recent result by Rachuri and Scholl (CRYPTO 2022) has achieved linear communication \(O(|C|\cdot n)\).