Theoretical Research On Quantum Secure Communication

Quantum communication provides a new way for securely transmitting secret message. The biggest advantage is its unconditional security and high-efficiency on the theory of quantum communication, Quantum communication has native advantage in the sense of security and it has gradually developed into a very important subject in the field of quantum information.Three areas in quantum communication are involved, i.e., eavesdropping detection strategy in the quantum secure direct communication、controlled teleportation and quantum communication protocol security analysis in the collective noise environment.In the field of eavesdropping detection strategy in the quantum secure direct communication, the improved eavesdropping detection strategy based on extended three-particle Greenberger-Horne-Zeilinger state is presented, and the security of the protocol is analyzed with the theory of information entropy. Through quantitative analysis of the relationship between eavesdropping probability and the amount of information, it can be proved that the eavesdropping detection methods proposed in this article is better.In the field of controlled teleportation, in order to teleport an unknown two-particle entangled state via a cluster state, a controlled teleportation scheme is proposed. The success probability of the proposed scheme reaches1.0.In the field of protocol security analysis in the collective noise environment, the security analysis of BBM92is presented, on the basis of noise processing model, with the theory of information entropy, the relationship among the maximum amount of information、bit error rate and noise level is analyzed. So as a quantum key distribution protocol, BBM92is secure in the collective noise environment.