Efficient Multi‐Party Semi‐Quantum Private Comparison Protocol Based on Bell States

An efficient multiparty semi‐quantum private comparison protocol based on Bell states is proposed. The proposed protocol enables the comparison of private information equality among multiple classical participants with the assistance of two semi‐honest third parties. Unlike previous protocols, the proposed protocol can be further extended to resist the collective‐dephasing noise and the collective‐rotation noise, respectively. The proposed protocol and its extensions do not require the classical participants to generate and send new quantum states to the third party, and these participants can compare two privacies within one round of comparison. In addition, the protocol performs better with a qubit efficiency up to 25%. The security analysis indicates that the protocol is resilient to various known quantum attacks. Furthermore, the feasibility of this protocol is confirmed by simulation results on the IBM quantum platform.