As an important topic in quantum secure multiparty computing, quantum privacy query (QPQ) can solve the problem of information query between users and database owners without compromising privacy. In the existing research, most of them focus on its functions, not its applications. In this paper, a new QPQ protocol based on two-particle states is proposed. In our protocol, we use two-particle states combined with the Ctrl or Shift operations to give the user a partial key sequence and the database cannot recognize the user's key sequence. Meanwhile, we conduct simulation experiments at the IBM quantum experience and show that it is feasible. We discuss its application in the private set intersection (PSI), which is derived from QPQ. According to our analysis, the QPQ protocol and PSI protocol are secure.
As an important topic in quantum secure multiparty computing, quantum privacy query (QPQ) can solve the problem of information query between users and database owners without compromising privacy. In the existing research, most of them focus on its functions, not its applications. In this paper, a new QPQ protocol based on two-particle states is proposed. In our protocol, we use two-particle states combined with the Ctrl or Shift operations to give the user a partial key sequence and the database cannot recognize the user's key sequence. Meanwhile, we conduct simulation experiments at the IBM quantum experience and show that it is feasible. We discuss its application in the private set intersection (PSI), which is derived from QPQ. According to our analysis, the QPQ protocol and PSI protocol are secure.
Abstract 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.
Private Set Intersection Cardinality (PSI-CA) is one of the most concerned issues with the protection of privacy, in which two parties jointly compute the intersection cardinality without revealing their respective private sets. There are important applications of PSI-CA in real society, e.g., strongly privacy-preserving data statistics in contact tracing for health authorities to fight the outbreaks of highly contagious diseases. In this paper, we present a novel quantum PSI-CA protocol, in which we adopt oblivious quantum key distribution, secure quantum summation and quantum counting algorithm. The proposed PSI-CA protocol not only ensures the approximatively perfect security but also achieves the linear communication complexity, i.e.,O(N). Furthermore, we define a new privacy protection problem, i.e., Privacy-preserving Condition Query (PCQ), and provide an efficient solution to the PCQ problem based on the proposed quantum PSI-CA protocol. Finally, we verify the correctness and the feasibility of the proposed quantum PSI-CA protocol by circuit simulations in IBM Qiskit.
Abstract 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.
Abstract Private Set Intersection (PSI) is a crucial Secure Multi-Party Computation (SMPC) primitive which enables participants to securely obtain the intersection of their private sets without revealing their individual set information. The advent of quantum computing threatens classical PSI protocols, driving the development of Quantum PSI (QPSI) alternatives. We propose a two-party QPSI protocol based on a semi-honest third party. This protocol achieves set intersection using only single-qubit unitary operations and single-qubit states. Security analysis shows that our protocol can resist common attacks. Validation experiments conducted on the IBM Qiskit simulator confirm the protocol's correctness and feasibility. Furthermore, we compare the proposed protocol with existing QPSI protocols in terms of quantum states, unitary operations, measurements, and fairness, demonstrating gains in quantum resource efficiency, fairness, and practical feasibility.
As an important branch of secure multi-party computation, privacy set intersection enables multiple parties to input their private sets and jointly compute the intersection of these sets without revealing any information other than the intersection itself. With the increasing demand for privacy protection of user data, privacy set intersection has been widely used in privacy computing and other fields. In this paper, we utilize the properties of mutually unbiased bases to propose a multi-party quantum private set intersection protocol that incorporates identity authentication mechanisms. A semi-honest third party (TP) is introduced to facilitate the secure execution of this task among the multiple participating parties. The TP establishes a shared master key with each party, which serves as the basis for authenticating the identity of each participant throughout the protocol. Single-particle quantum states, prepared by the TP, act as the information carriers and are sequentially transmitted among the participating parties. Each party performs a local unitary operation on the circulating particle, thereby encoding their private data within the quantum state. At the end of the protocol, the TP announces his measurement result, by which all participants can concurrently ascertain the intersection of their private data sets. Notably, the proposed protocol eliminates the need for long-term storage of single-particle quantum states, thereby rendering it feasible with existing quantum technological capabilities. Furthermore, a comprehensive security analysis demonstrates that the protocol effectively resists some common external and internal attacks, thereby ensuring its theoretical security.
Like addition, subtraction, multiplication and division, logical AND is a fundamental arithmetic operation in scientific computing. In this paper, we first consider and define a new privacy-preserving problem, i.e., Secure Multiparty Logical AND (SMLA), in which multiple participants can jointly compute the logical AND of their respective private bits. Furthermore, we present a novel quantum SMLA protocol by employing phase-matching quantum conference key agreement and perfect quantum encryption, and design the corresponding quantum circuits. The proposed quantum SMLA protocol can ensure information-theoretical security. What’s more, we design a private grouping strategy to reduce the communicational complexity and accordingly present an improved quantum SMLA protocol with the linear communicational rounds. In addition, we investigate its applications and design a feasible quantum Multiparty Private Set Intersection Cardinality (MPSI-CA) protocol based on the improved quantum SMLA protocol, in which multiple participants jointly compute the intersection cardinality without revealing their respective private sets. Finally, we verify the correctness and the feasibility of the proposed quantum protocols by circuit simulations in IBM Qiskit.