QKD-Based Quantum Private Query Protocol in the Single-Photon Interference Communication System

In this paper, we propose a quantum-key-distribution-based quantum private query protocol (QKD-based QPQ) utilizing the uncertainty relation of the photon path and the interference result in the single-photon interference circuit. The proposed protocol is loss-tolerant and easy to be realized in the quantum communication systems based on single-photon interference. Without any assumption on the dishonest party’s computation ability, we prove that the dishonest user can only steal a little more than one item from the database, and any dishonest action of the database would be found by the user with a nonzero probability. Compared with other QKD-based QPQ protocols utilizing single-photon interference, the proposed protocol uses less quantum devices, which means the costs of the proposed protocol is lower.