Cloud computing is a powerful and popular information technology paradigm that enables data service outsourcing and provides higher-level services with minimal management effort. However, it is still a key challenge to protect data privacy when a user accesses the sensitive cloud data. Privacy-preserving database query allows the user to retrieve a data item from the cloud database without revealing the information of the queried data item, meanwhile limiting user’s ability to access other ones. In this study, in order to achieve the privacy preservation and reduce the communication complexity, a quantum-based database query scheme for privacy preservation in cloud environment is developed. Specifically, all the data items of the database are firstly encrypted by different keys for protecting server’s privacy, and in order to guarantee the clients’ privacy, the server is required to transmit all these encrypted data items to the client with the oblivious transfer strategy. Besides, two oracle operations, a modified Grover iteration, and a special offset encryption mechanism are combined together to ensure that the client can correctly query the desirable data item. Finally, performance evaluation is conducted to validate the correctness, privacy, and efficiency of our proposed scheme.
Cloud computing is a powerful and popular information technology paradigm that enables data service outsourcing and provides higher-level services with minimal management effort. However, it is still a key challenge to protect data privacy when a user accesses the sensitive cloud data. Privacy-preserving database query allows the user to retrieve a data item from the cloud database without revealing the information of the queried data item, meanwhile limiting user’s ability to access other ones. In this study, in order to achieve the privacy preservation and reduce the communication complexity, a quantum-based database query scheme for privacy preservation in cloud environment is developed. Specifically, all the data items of the database are firstly encrypted by different keys for protecting server’s privacy, and in order to guarantee the clients’ privacy, the server is required to transmit all these encrypted data items to the client with the oblivious transfer strategy. Besides, two oracle operations, a modified Grover iteration, and a special offset encryption mechanism are combined together to ensure that the client can correctly query the desirable data item. Finally, performance evaluation is conducted to validate the correctness, privacy, and efficiency of our proposed scheme.
Abstract Cloud computing, as a popular technology in recent years, has greatly facilitated the development of data outsourcing services. However, when users access sensitive data stored in the cloud, ensuring the security of data remains a pressing challenge. In this paper, we present a privacy-preserving keyword query scheme for outsourced data in cloud environment. Furthermore, to implement this scheme, we propose a series of quantum basic protocols with single qubits. The proposed basic protocols do not require the execution of quantum gate operations, and the necessary measurements are only Bell measurements based on measurement-device-independence. Therefore, it is practical and feasible under current technology. Moreover, compared with classical schemes, our scheme has higher security (i.e., quantum security). Finally, we conduct simulation experiments in IBM Qiskit to verify the correctness and feasibility of the critical parts of the scheme.
Quantum key distribution (QKD)-based quantum private query (QPQ) is a practical application of QKD, which relaxes the security condition of perfectly concealing a private query to a cheating-sensitive strategy. We propose a QPQ protocol based on the delegated QKD scheme (DQKD-based QPQ), in which two almost 'classical' clients (data user and database owner) can establish a 1-out-of-N oblivious key with the help of a cloud server with full quantum ability. Concretely, the two classical participants in the DQKD-based QPQ only need to access the quantum channel and reorder qubits, and the costly quantum operations, quantum state preparation and measurement are outsourced to a full quantum server in the cloud without leaking participants' privacy. The proposed protocol not only provides a cloud-based framework of QKD-based QPQ, but also obtains better security by a real-time security check, which can protect the security of the database and user against all potential attacks even if the quantum server is assumed to be a powerfully untrusted adversary .
With the rapid development of IoT technology, securely querying sensitive data collected by devices within a specific range has become a focal concern for users. This paper proposes a privacy-preserving range query scheme based on quantum encryption, along with circuit simulations and performance analysis. We first propose a quantum private set similarity comparison protocol and then construct a privacy-preserving range query scheme for IoT environments. By leveraging the properties of quantum homomorphic encryption, the proposed scheme enables encrypted data comparisons, effectively preventing the leakage of sensitive data. The correctness and security analysis demonstrates that the designed protocol guarantees users receive the correct query results while resisting both external and internal attacks. Moreover, the protocol requires only simple quantum states and operations, and does not require users to bear the cost of complex quantum resources, making it feasible under current technological conditions.
Searchable encryption (SE) is a positive way to protect users sensitive data in cloud computing setting, while preserving search ability on the server side, i.e., it allows the server to search encrypted data without leaking information about the plaintext data. In this paper, a multi-client universal circuit-based full-blind quantum computation (FBQC) model is proposed. In order to meet the requirements of multiclient accessing or computing encrypted cloud data, all clients with limited quantum ability outsource the key generation to a trusted key center and upload their encrypted data to the data center. Considering the feasibility of physical implementation, all quantum gates in the circuit are replaced with the combination of π/8 rotation operator set {Rz(π/4), Ry(π/4), CRz(π/4), CRy(π/4), CCRz(π/4), CCRy(π/4)}. In addition, the data center is only allowed to perform one π/8 rotation operator each time, but does not know the structure of the circuit (i.e., quantum computation), soit can guarantee the blindness of computation. Then, through combining this multi-client FBQC model and Grover searching algorithm, we continue to propose a quantum searchable encryption scheme for cloud data. It solves the problem of multi-client access mode under searchable encryption in the cloud environment, and has the ability to resist against some quantum attacks. To better demonstrate our scheme, an example of our scheme to search on encrypted 2-qubit state is given in detail. Furthermore, the security of our scheme is analysed from two aspects: external attacks and internal attacks, and the result indicates that it can resist against such kinds of attacks and also guarantee the blindness of data and computation.
Range query in cloud-based outsourcing applications is an important data search service, but it can suffer from privacy disclosure. In this paper, to enhance the security and privacy of sensitive data, we introduce quantum cryptographic technologies and present a feasible quantum approach to address an important range query, i.e., privacy-preserving range MAX/MIN query. First, we define a primitive protocol of secure multiparty computations, called Oblivious Set Inclusion Decision (OSID), in which two parties jointly decide whether a private set includes another private set in an oblivious way, and present an efficient OSID quantum protocol. Especially, in order to efficiently implement OSID quantum protocol, we design a single-photon-based quantum protocol for computing XOR of two private bits, which can achieve the information-theoretical security with the help of a non-colluding quantum cloud. Finally, we propose a novel quantum scheme for privacy-preserving range MAX/MIN query in edge-based Internet of Things by using OSID quantum protocols. Compared with the classical related schemes, our proposed quantum scheme has higher security (i.e., quantum security), because the security of our proposed protocols is based on the basic physical principles of quantum mechanics, instead of unproven computational difficulty assumptions.
We propose a cheat sensitive quantum protocol to perform a private search on a classical database which is efficient in terms of communication complexity. It allows a user to retrieve an item from the database provider without revealing which item he or she retrieved: if the provider tries to obtain information on the query, the person querying the database can find it out. The protocol ensures also perfect data privacy of the database: the information that the user can retrieve in a single query is bounded and does not depend on the size of the database. With respect to the known (quantum and classical) strategies for private information retrieval, our protocol displays an exponential reduction in communication complexity and in running-time computational complexity.