Secure Private Comparison of Equality using Quantum Resources

Abstract

Private comparison of equality is an essential task in secure multiparty computation. In this paper, we investigate such a task in quantum settings. Particularly, we design a comparison protocol using quantum resources. The protocol allows three users to verify whether the private inputs of three users are identical and preserve their inputs’ privacy without an extra third party who can help the verifying process. The proposed protocol does not require unitary operations for the information encoding, which, to some extent, facilitates the protocol’s implementation. In addition, the Trojan horse attacks are invalid to the proposed protocol as it only employs one-step quantum transmissions. We also show that the presented protocol is secure against some well-known attacks.