Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, China.
Synergetic Innovation Center of Quantum Information &Quantum Physics, University of Science and Technology of China, Hefei, 230026, China.
Sci Rep. 2017 Jan 4;7:39733. doi: 10.1038/srep39733.
Quantum private queries (QPQ) is an important cryptography protocol aiming to protect both the user's and database's privacy when the database is queried privately. Recently, a variety of practical QPQ protocols based on quantum key distribution (QKD) have been proposed. However, for QKD-based QPQ the user's imperfect detectors can be subjected to some detector- side-channel attacks launched by the dishonest owner of the database. Here, we present a simple example that shows how the detector-blinding attack can damage the security of QKD-based QPQ completely. To remove all the known and unknown detector side channels, we propose a solution of measurement-device-independent QPQ (MDI-QPQ) with single- photon sources. The security of the proposed protocol has been analyzed under some typical attacks. Moreover, we prove that its security is completely loss independent. The results show that practical QPQ will remain the same degree of privacy as before even with seriously uncharacterized detectors.
量子私有查询（QPQ）是一种重要的密码学协议，旨在保护用户和数据库的隐私，当数据库被私下查询时。最近，提出了各种基于量子密钥分发（QKD）的实用 QPQ 协议。然而，对于基于 QKD 的 QPQ，用户的不完美探测器可能会受到数据库不诚实所有者发起的一些探测器侧信道攻击。在这里，我们提出了一个简单的例子，展示了探测器盲攻击如何完全破坏基于 QKD 的 QPQ 的安全性。为了消除所有已知和未知的探测器侧信道，我们提出了一种使用单光子源的测量设备无关 QPQ（MDI-QPQ）的解决方案。在一些典型的攻击下，对所提出的协议的安全性进行了分析。此外，我们证明了它的安全性是完全与损失无关的。结果表明，即使使用严重特征不明的探测器，实际的 QPQ 仍将保持相同程度的隐私。
