Towards Building Scalable Constant-Round MPC from Minimal Assumptions via Round Collapsing

Vipul Goyal, Junru Li, Rafail Ostrovsky, Yifan Song

Abstract: In this work, we study the communication complexity of constant-round secure multiparty computation (MPC) against a fully malicious adversary and consider both the honest majority setting and the dishonest majority setting. In the (strong) honest majority setting (where \(t=(1/2-\epsilon )n\) for a constant \(\epsilon \)), the best-known result without relying on FHE is given by Beck et al. (CCS 2023) based on the LPN assumption that achieves \(O(|C|\kappa )\) communication, where \(\kappa \) is the security parameter and the achieved communication complexity is independent of the number of participants. In the dishonest majority setting, the best-known result is achieved by Goyal et al. (ASIACRYPT 2024), which requires \(O(|C|n\kappa )\) bits of communication and is based on the DDH and LPN assumptions.