A private set intersection protocol based on multi-party quantum computation for greatest common divisor

Private set intersection (PSI) is a cryptographic primitive that allows two or more parties to learn the intersection of their input sets and nothing else. In this paper, we present a private set intersection protocol based on a new secure multi-party quantum protocol for greatest common divisor (GCD). The protocol is mainly inspired by the recent quantum private set union protocol based on least common multiple by Liu, Yang, and Li. Performance analysis guarantees the correctness and it also shows that the proposed protocols are completely secure in semi-honest model. Moreover, the complexity is proven to be efficient (poly logarithmic) in the size of the input sets

Multi-party Private Set Operations with an External Decider

A Private Set Operation (PSO) protocol involves at least two parties with their private input sets. The goal of the protocol is to learn the output of a set operation, e.g., set intersection, on the parties' input sets, without revealing any information about the items that are not in the output set. Commonly, the outcome of the set operation is revealed to parties and no one else. However, in many application areas of PSO, the result of the set operation should be learned by an external participant who does not have an input set. We call this participant the decider. In this paper, we present new variants of multi-party PSO, for the external decider setting. All parties except the decider have a private set. Parties other than the decider neither learn this result, nor anything else from this protocol. Moreover, we studied generic solutions to the problem of PSO in the presence of an external decider.Peer reviewe