Device-independent quantum private comparison protocol without a third party

TL;DR

This paper introduces a device-independent quantum private comparison protocol involving only two parties, enhancing practicality and security by reducing reliance on trust assumptions in quantum cryptography.

Contribution

It extends a previous two-party QPC protocol to a device-independent version, improving security and practicality in quantum private comparisons.

Findings

Protocol leaks minimal information

Device independence enhances security

Practical applicability improved

Abstract

Since unconditionally secure quantum two-party computations are known to be impossible, most existing quantum private comparison (QPC) protocols adopted a third party. Recently, we proposed a QPC protocol which involves two parties only, and showed that although it is not unconditionally secure, it only leaks an extremely small amount of information to the other party. Here we further propose the device-independent version of the protocol, so that it can be more convenient and dependable in practical applications.