Quantum Private Query Based on Bell State and Single Photons

Quantum private query (QPQ) can protect both user’s and database holder’s privacy. In this paper, we propose a novel quantum private query protocol based on Bell state and single photons. As far as we know, no one has ever proposed the QPQ based on Bell state. By using the decoherence-free (DF) states, our protocol can resist the collective noise. Besides that, our protocol is a one-way quantum protocol, which can resist the Trojan horse attack and reduce the communication complexity. Our protocol can not only guarantee the participants’ privacy but also stand against an external eavesdropper.