Privacy-Preserving Distributed Set Intersection

With the growing demand of databases outsourcing and its security concerns, we investigate privacy-preserving set intersection in a distributed scenario. We propose a one-round protocol for privacy-preserving set intersection based on a combination of secret sharing scheme and ho- momorphic encryption. We then show that, with an extra permutation performed by each contacted server, the cardinality of set intersection can be computed efficiently. All protocols constructed in this paper are provably secure against an honest-but-curious adversary under the Decisional Diffie-Hellman assumption.