基于量子第三方的隐私数据库查询协议

Private Database Queries With a Quantum Third Party

保障查询数据库时用户及数据库的隐私性具有重要意义。该文利用三光子GHZ(Greenberger-HorneZeilinger)态的量子关联性,提出一个基于量子第三方的隐私数据库查询协议。协议对于信道损耗具有很高的容忍度,并且能够有效地抵抗第三方发动伪造量子纠缠态和量子记忆存储攻击。在第三方的帮助下,协议能够确定地控制用户获得数据库隐私信息的数量。同时,利用Mermin-Bell不等式进行真正的三方纠缠验证保证协议的安全性,这一思想也拓展了设备无关纠缠验证的应用领域。

It is of great importance to guarantee the privacy of the database and users when the database is being queried. A private database queries protocol based on a quantum Third Party （TP） is proposed by utilizing the quantum correlation of three-photon Greenberger-Horne-Zeilinger （GHZ） states. The proposed protocol is highly tolerant of channel loss and robust against fake entangled state attack and quantum memory attack implemented by the third party. With the help of the TP, the amount of private information obtained by the users from the database is deterministically controllable in the proposed protocol. Furthermore, the true tripartite entanglement witness by using Mermin-Bell inequality can ensure the security of the protocol, which expands the application area of Device-Independent （DI） entanglement witnesses.