Research On Quantum Private Query With Authentication

Symmetrically private information retrieval(SPIR),which refers to a user purchases data from a database provider under the condition of ensuring the privacy of both parties.Specifically,the user should not access data other than those she bought,and the database provider can not know what data the user has obtained.The security of SPIR is based on the mathematical difficulty problem,quantum private query is the quantum improved version of SPIR,its security is guaranteed by quantum information theory,and it has significant advantages in communication and computational complexity.The existing quantum private query includes Oracle-based and QKD-based two types of protocols,the former is difficult to realize for the reason,the dimension of the unitary operation will be increased with the large database.While the QKD-based quantum private query protocols,using the same measurement method and information carrier states as BB84 QKD protocol,are easy to implement with existing technologies and have more practical significance.Therefore,this thesis mainly concentrates on QKD-based quantum private query.The existing QKD-based quantum private query protocols focus on privacy protection and ignore other attacks from outside attackers,such as impersonation,“man-in-the-middle” and tampering.Undoubtedly,these attacks can destroy the quantum private query process.In this thesis,starting from two types of quantum private query protocols,single user and multi-user,it proposes secure single user and multi-user quantum private query protocols that can resist external active attacks by designing different authentication mechanisms.1.A single user quantum private query protocol with authentication is proposed.The protocol uses single photon quantum resources to design an identity authentication mechanism and integrating it into the existing QKD-based quantum private query protocol.The proposed protocol implements mutual identity authentication in the oblivious key agreement phase;Besides,the mutual authentication process also generates a shared key between Alice and Bob to achieve the data source authentication and integrity protection in the data retrieval phase.The security analysis demonstrates that the proposed protocol not only retains the privacy protection strength of the original single user quantum private query protocol,but also has strong resistance to impersonation,“man-in-the-middle” and tempering attacks.2.A multi-user quantum private query protocol with authentication is proposed.The protocol introduces the trusted third party and uses the entanglement swapping technology of multi-particle GHZ state,by designing a multiparty simultaneous quantum identity authentication mechanism and integrating it into the existing QKD-based multi-user quantum private query protocol.The proposed protocol implements multiparty mutual identity authentication in the oblivious key agreement phase,the core idea of the protocol is to transform the mutual identity authentication between multi-user and the database provider into the authentication of all participants to the trusted third party.The security analysis demonstrates that the proposed protocol not only retains the privacy protection strength of the original multi-user quantum private query protocol,but also has strong resistance to impersonation and“man-in-the-middle” attacks.In general,the research objective of this thesis is to design security enhancement schemes which can be appropriate for QKD-based single user and multi-user quantum private query by quantum authentication technology.