Secure Multi-Party Quantum Private Information Query

Different from the existing quantum key distribution (QKD)-based quantum private query (QPQ) protocols, we propose a secure multi-party quantum private information query protocol utilizing universal blind quantum computation in quantum cloud computing. Due to the blindness and correctness of blind quantum computation, our protocol guarantees the privacy and security for all the clients and the servers. The clients obtain values corresponding to their queries only, and nothing else from the servers, while the servers can not get any information about the queries. In our protocols, the only thing that the clients do is to need the ability to perform single-qubit measurement or to prepare single-qubit states.