Efficient Linear Multiparty PSI and Extensions to Circuit/Quorum PSI

Abstract

Multiparty Private Set Intersection (mPSI), enables n parties, each holding private sets (each of size m) to securely compute the intersection of these private sets. While several protocols are known for this task, the only concretely efficient protocol is due to the work of Kolesnikov et al. (KMPRT, CCS 2017), who gave a semi-honest secure protocol with communication complexity O(nmtƛ), where t < n is the number of corrupt parties and ƛ is the security parameter. In this work, we make the following contributions: