In order to protect the privacy of the query user and database,some QKD-based quantum private query(QPQ)protocols were proposed.One example is the protocol proposed by Zhou et al,in which the user makes initial quantu...In order to protect the privacy of the query user and database,some QKD-based quantum private query(QPQ)protocols were proposed.One example is the protocol proposed by Zhou et al,in which the user makes initial quantum states and derives the key bit by comparing the initial quantum state and the outcome state returned from the database by ctrl or shift mode,instead of announcing two non-orthogonal qubits as others which may leak part secret information.To some extent,the security of the database and the privacy of the user are strengthened.Unfortunately,we find that in this protocol,the dishonest user could be obtained,utilizing unambiguous state discrimination,much more database information than that is analyzed in Zhou et al's original research.To strengthen the database security,we improved the mentioned protocol by modifying the information returned by the database in various ways.The analysis indicates that the security of the improved protocols is greatly enhanced.展开更多
In order to protect the privacy of query user and database,some QKD-based quantum private query(QPQ)protocols were proposed.Unfortunately some of them cannot resist internal attack from database perfectly;some others ...In order to protect the privacy of query user and database,some QKD-based quantum private query(QPQ)protocols were proposed.Unfortunately some of them cannot resist internal attack from database perfectly;some others can ensure better user privacy but require a reduction of database privacy.In this paper,a novel two-way QPQ protocol is proposed to ensure the privacy of both sides of communication.In our protocol,user makes initial quantum states and derives the key bit by comparing initial quantum state and outcome state returned from database by ctrl or shift mode instead of announcing two non-orthogonal qubits as others which may leak part secret information.In this way,not only the privacy of database be ensured but also user privacy is strengthened.Furthermore,our protocol can also realize the security of loss-tolerance,cheat-sensitive,and resisting JM attack etc.展开更多
Quantum private query(QPQ)protocols have emerged as a pivotal innovation in quantum cryptography,offering users the ability to retrieve specific database information while preserving privacy.However,the practical impl...Quantum private query(QPQ)protocols have emerged as a pivotal innovation in quantum cryptography,offering users the ability to retrieve specific database information while preserving privacy.However,the practical implementation of these protocols faces significant security challenges,particularly from joint-measurement attacks in multi-round query scenarios.A recent study by Liu et al.addresses these vulnerabilities through a comprehensive analysis and proposes innovative solutions,marking a critical advancement in the field[1].展开更多
Quantum private query(QPQ)protocols based on quantum key distribution(QKD)have gained significant attention due to their practical implementation advantages.However,joint-measurement attacks pose a serious threat to t...Quantum private query(QPQ)protocols based on quantum key distribution(QKD)have gained significant attention due to their practical implementation advantages.However,joint-measurement attacks pose a serious threat to their security,especially in real-world multi-query scenarios.Most existing QKD-based QPQ protocols become highly vulnerable when users make repeated database queries.Attackers can exploit strategies like minimum error discrimination(MED)and unambiguous state discrimination(USD)to completely break database security.This work thoroughly analyzes joint-measurement attacks in multi-round QPQ systems.We demonstrate that these attacks make current protocols practically unusable.To address this critical issue,we propose an effective defense method using classical post-processing.Our solution not only reveals fundamental flaws in existing approaches but also provides a reliable way to build secure QPQ systems.These findings enable the development of robust protocols that can withstand real-world usage patterns,moving QPQ technology from theory to practical application.展开更多
In this paper, we present a quantum-key-distribution(QKD)-based quantum private query(QPQ) protocol utilizing single-photon signal of multiple optical pulses. It maintains the advantages of the QKD-based QPQ, i.e., ea...In this paper, we present a quantum-key-distribution(QKD)-based quantum private query(QPQ) protocol utilizing single-photon signal of multiple optical pulses. It maintains the advantages of the QKD-based QPQ, i.e., easy to implement and loss tolerant. In addition, different from the situations in the previous QKD-based QPQ protocols, in our protocol, the number of the items an honest user will obtain is always one and the failure probability is always zero. This characteristic not only improves the stability(in the sense that, ignoring the noise and the attack, the protocol would always succeed), but also benefits the privacy of the database(since the database will no more reveal additional secrets to the honest users). Furthermore, for the user's privacy, the proposed protocol is cheat sensitive, and for security of the database, we obtain an upper bound for the leaked information of the database in theory.展开更多
The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows th...The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows that multiphoton pulses have posed a serious threat to the participant’s privacy in QPQ protocols.Then we propose a decoy-state method that can help the honest participant detect the attack by exploiting multiphoton pulses and improving the key distillation process to defend against such attack.The analysis demonstrates that our decoy-state method significantly improves the security of the QPQ with weak coherent pulses,which solves a major obstacle in the practical application of the QPQ.展开更多
Quantum channel noise may cause the user to obtain a wrong answer and thus misunderstand the database holder for existing QKD-based quantum private query(QPQ) protocols. In addition, an outside attacker may conceal hi...Quantum channel noise may cause the user to obtain a wrong answer and thus misunderstand the database holder for existing QKD-based quantum private query(QPQ) protocols. In addition, an outside attacker may conceal his attack by exploiting the channel noise. We propose a new, robust QPQ protocol based on four-qubit decoherence-free(DF) states. In contrast to existing QPQ protocols against channel noise, only an alternative fixed sequence of single-qubit measurements is needed by the user(Alice) to measure the received DF states. This property makes it easy to implement the proposed protocol by exploiting current technologies. Moreover, to retain the advantage of flexible database queries, we reconstruct Alice's measurement operators so that Alice needs only conditioned sequences of single-qubit measurements.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFC3801700)the National Natural Science Foundation of China(Grant No.62472052)Xinjiang Production and Construction Corps Key Laboratory of Computing Intelligence and Network Information Security(Grant No.CZ002702-3)。
文摘In order to protect the privacy of the query user and database,some QKD-based quantum private query(QPQ)protocols were proposed.One example is the protocol proposed by Zhou et al,in which the user makes initial quantum states and derives the key bit by comparing the initial quantum state and the outcome state returned from the database by ctrl or shift mode,instead of announcing two non-orthogonal qubits as others which may leak part secret information.To some extent,the security of the database and the privacy of the user are strengthened.Unfortunately,we find that in this protocol,the dishonest user could be obtained,utilizing unambiguous state discrimination,much more database information than that is analyzed in Zhou et al's original research.To strengthen the database security,we improved the mentioned protocol by modifying the information returned by the database in various ways.The analysis indicates that the security of the improved protocols is greatly enhanced.
基金Supported by National Natural Science Foundation of China under Grant Nos.U1636106,61572053,61472048,61602019,61502016Beijing Natural Science Foundation under Grant Nos.4152038,4162005+1 种基金Basic Research Fund of Beijing University of Technology(No.X4007999201501)The Scientific Research Common Program of Beijing Municipal Commission of Education under Grant No.KM201510005016
文摘In order to protect the privacy of query user and database,some QKD-based quantum private query(QPQ)protocols were proposed.Unfortunately some of them cannot resist internal attack from database perfectly;some others can ensure better user privacy but require a reduction of database privacy.In this paper,a novel two-way QPQ protocol is proposed to ensure the privacy of both sides of communication.In our protocol,user makes initial quantum states and derives the key bit by comparing initial quantum state and outcome state returned from database by ctrl or shift mode instead of announcing two non-orthogonal qubits as others which may leak part secret information.In this way,not only the privacy of database be ensured but also user privacy is strengthened.Furthermore,our protocol can also realize the security of loss-tolerance,cheat-sensitive,and resisting JM attack etc.
文摘Quantum private query(QPQ)protocols have emerged as a pivotal innovation in quantum cryptography,offering users the ability to retrieve specific database information while preserving privacy.However,the practical implementation of these protocols faces significant security challenges,particularly from joint-measurement attacks in multi-round query scenarios.A recent study by Liu et al.addresses these vulnerabilities through a comprehensive analysis and proposes innovative solutions,marking a critical advancement in the field[1].
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3801700)the National Natural Science Foundation of China(Grant Nos.62472052,62272073,and 62171418)+1 种基金the Sichuan Science and Technology Program(Grant No.2023JDRC0017)the Xinjiang Production and Construction Corps Key Laboratory of Computing Intelligence and Network Information Security(Grant No.CZ002702-3)。
文摘Quantum private query(QPQ)protocols based on quantum key distribution(QKD)have gained significant attention due to their practical implementation advantages.However,joint-measurement attacks pose a serious threat to their security,especially in real-world multi-query scenarios.Most existing QKD-based QPQ protocols become highly vulnerable when users make repeated database queries.Attackers can exploit strategies like minimum error discrimination(MED)and unambiguous state discrimination(USD)to completely break database security.This work thoroughly analyzes joint-measurement attacks in multi-round QPQ systems.We demonstrate that these attacks make current protocols practically unusable.To address this critical issue,we propose an effective defense method using classical post-processing.Our solution not only reveals fundamental flaws in existing approaches but also provides a reliable way to build secure QPQ systems.These findings enable the development of robust protocols that can withstand real-world usage patterns,moving QPQ technology from theory to practical application.
基金supported by the National Natural Science Foundation of China(Grant Nos.61272057 and 61170270)Beijing Higher Education Young Elite Teacher Project(Grant Nos.YETP0475 and YETP0477)Beijing University of Posts and Telecommunications Excellent Ph.D.Students Foundation(Grant No.CX201442)
文摘In this paper, we present a quantum-key-distribution(QKD)-based quantum private query(QPQ) protocol utilizing single-photon signal of multiple optical pulses. It maintains the advantages of the QKD-based QPQ, i.e., easy to implement and loss tolerant. In addition, different from the situations in the previous QKD-based QPQ protocols, in our protocol, the number of the items an honest user will obtain is always one and the failure probability is always zero. This characteristic not only improves the stability(in the sense that, ignoring the noise and the attack, the protocol would always succeed), but also benefits the privacy of the database(since the database will no more reveal additional secrets to the honest users). Furthermore, for the user's privacy, the proposed protocol is cheat sensitive, and for security of the database, we obtain an upper bound for the leaked information of the database in theory.
基金supported by the National Natural Science Foundation of China(Grant Nos.62171418,U19A2076,61901425,and 61702061)Natural Science Foundation of Chongqing(Grant No.cstc2020jcyjmsxm X0719)+2 种基金National Science Key Lab Fund Project(Grant No.6142103200105)Fundamental Research Funds for the Central Universities(Grant Nos.2020CDJQY-A018,and 2020CDJ-LHZZ-056)Sichuan Science and Technology Program(Grant No.019JDJQ0060)。
文摘The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows that multiphoton pulses have posed a serious threat to the participant’s privacy in QPQ protocols.Then we propose a decoy-state method that can help the honest participant detect the attack by exploiting multiphoton pulses and improving the key distillation process to defend against such attack.The analysis demonstrates that our decoy-state method significantly improves the security of the QPQ with weak coherent pulses,which solves a major obstacle in the practical application of the QPQ.
基金supported by the National Natural Science Foundation of China(Grant Nos.61572053,61671087,and 61602019)and the Beijing Natural Science Foundation(Grant Nos.4162005,and 4152038)
文摘Quantum channel noise may cause the user to obtain a wrong answer and thus misunderstand the database holder for existing QKD-based quantum private query(QPQ) protocols. In addition, an outside attacker may conceal his attack by exploiting the channel noise. We propose a new, robust QPQ protocol based on four-qubit decoherence-free(DF) states. In contrast to existing QPQ protocols against channel noise, only an alternative fixed sequence of single-qubit measurements is needed by the user(Alice) to measure the received DF states. This property makes it easy to implement the proposed protocol by exploiting current technologies. Moreover, to retain the advantage of flexible database queries, we reconstruct Alice's measurement operators so that Alice needs only conditioned sequences of single-qubit measurements.
