An Efficient Semi-Quantum Private Comparison Protocol Based on Entanglement Swapping of Four-Particle Cluster State and Bell State

Semi-quantum private comparison(SQPC) is the quantum method to compare the secrets' equality for two distrustful classical participants without knowing the their accurate information. The four-particle cluster state is more robust against decoherence than any other four-particle state. In this paper, the novel entanglement swapping construction by the four-particle cluster state and Bell state can perform this SQPC protocol well. With the pre-shared secret key sequence, the two distrustful users can obtain promising results without leaking any information to the semi-honest third party (TP). Then, the security analyses indicate that this SQPC protocol is secure against the outside and participant attacks, and more efficient than the similar literature.