title: Loss-tolerant measurement-device-independent quantum private queries.
abstract: 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.
authors.affiliation: 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.
authors.forename: Liang-Yuan
authors.initials: LY
authors.lastname: Zhao
authors.affiliation: 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.
authors.forename: Zhen-Qiang
authors.initials: ZQ
authors.lastname: Yin
authors.affiliation: 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.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: 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.
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Qian
authors.affiliation: 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.
authors.forename: Chun-Mei
authors.initials: CM
authors.lastname: Zhang
authors.affiliation: 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.
authors.forename: Guang-Can
authors.initials: GC
authors.lastname: Guo
authors.affiliation: 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.
authors.forename: Zheng-Fu
authors.initials: ZF
authors.lastname: Han