International Association
for Cryptologic Research

Most existing MPC protocols consider the homogeneous setting, where all the MPC players are assumed to have identical communication and computation resources. In practice, the weakest player often becomes the bottleneck of the entire MPC protocol execution. In this work, we initiate the study of so-called load-balanced MPC in the heterogeneous computing. A load-balanced MPC protocol can adjust the workload of each player accordingly to maximize the overall resource utilization. In particular, we propose new notions called composite circuit and composite garbling scheme, and construct two efficient server-aided protocols with malicious security and semi-honest security, respectively. Our maliciously secure protocol is over 400$\times$ faster than the authenticated garbling protocol (CCS'17); our semi-honest protocol is up to 173$\times$ faster than the optimized BMR protocol (CCS'16).