In this paper, by using entanglement swapping of Bell states, an efficient quantum private comparison(QPC) protocol with a semi-honest party is proposed. The semi-honest third party (TP) is required to help two participants perform the comparison. She can record intermediate results and do some calculations in the whole process of the protocol execution, but she is not allowed to conspire with any participants. Moreover, TP cannot get two participants’ privacy information except the comparison results. The security analysis shows that the proposed protocol can resist both outsider attacks and insider attacks. Compared with other similar QPC protocols, the proposed one needs neither unitary operations nor the entanglement swapping of multiparticle quantum states, and it only needs the entanglement swapping of Bell states, which makes it more practical. Since three-bit classical information could be compared in each comparison, the proposed protocol has a good performance in its efficiency.

在本文中，利用贝尔状态的纠缠交换，提出了一种具有半诚实方的高效量子私有比较（QPC）协议。需要半诚实的第三方（TP）来帮助两个参与者进行比较。她可以在协议执行的整个过程中记录中间结果并做一些计算，但她不能与任何参与者合谋。此外，除了比较结果之外，TP 无法获得两个参与者的隐私信息。安全性分析表明，该协议可以抵抗外部攻击和内部攻击。与其他类似的QPC协议相比，所提出的协议既不需要幺正运算，也不需要多粒子量子态的纠缠交换，只需要贝尔态的纠缠交换，这使它更实用。由于每次比较都可以比较三位经典信息，因此所提出的协议在效率方面具有良好的性能。