Relativistic quantum private database queries

Yu‐Guang Yang, Ming-Ou Zhang, Rui Zhe Yang

Lili Yan, Dongmei Liu, Shibin Zhang +2 more

Fei Gao

Tian‐Yin Wang, Shuyu Wang, Jianfeng Ma

Chuan Xi Wang, Liang Hao, Lian-Jie Zhao

We present a modified protocol for the realization of a quantum private query process on a classical database. Using one-qubit query and CNOT operation, the query process can be realized in a two-mode database. In the query process, the data privacy is preserved as the sender would not reveal any information about the database besides her query information, and the database provider cannot retain any information about the query. We implement the quantum private query protocol in a nuclear magnetic resonance system. The density matrix of the memory registers are constructed.

Vittorio Giovannetti, Seth Lloyd, Lorenzo Maccone

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.