Multi-party Private Set Operations with an External Decider

TL;DR

This paper introduces new multi-party private set operation protocols involving an external decider who learns the result without revealing or learning anything about individual inputs, enhancing privacy in collaborative data analysis.

Contribution

It proposes novel variants of multi-party private set operations with an external decider and provides a generic solution framework for these protocols.

Findings

Protocols ensure only the decider learns the set operation result.

Maintains privacy of individual input sets for all other parties.

Offers a flexible, generic approach to multi-party private set operations.

Abstract

A Private Set Operation (PSO) protocol involves at least two parties with their private input sets. The goal of the protocol is for the parties to learn the output of a set operation, i.e. set intersection, on their 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 whom does not have an input set. We call this participant the decider. In this paper, we present new variants of multi-party PSO, where there is a decider who gets the result. All parties expect the decider have a private set. Other parties neither learn this result, nor anything else about this protocol. Moreover, we present a generic solution to the problem of PSO.