Private Set Intersection with Delegated Blind Quantum Computing

TL;DR

This paper introduces a quantum protocol enabling two classical parties to securely compute their set intersection with a quantum server, preserving privacy and achieving linear quantum communication complexity.

Contribution

It presents the first server-aided private set intersection protocol using delegated blind quantum computing with security against malicious servers.

Findings

Protocol is correct and secure.

Privacy is preserved against a malicious quantum server.

Quantum communication complexity is linear in input size.

Abstract

Private set intersection is an important problem with implications in many areas, ranging from remote diagnostics to private contact discovery. In this work, we consider the case of two-party PSI in the honest-but-curious setting. We propose a protocol that solves the server-aided PSI problem using delegated blind quantum computing. More specifically, the proposed protocol allows Alice and Bob (who do not have any quantum computational resources or quantum memory) to interact with Steve (who has a quantum computer) in order for Alice and Bob to obtain set intersection such that privacy is preserved. In particular, Steve learns nothing about the clients' input, output, or desired computation. The proposed protocol is correct, secure and blind against a malicious server, and characterized by a quantum communication complexity that is linear in the input size.