Research On Several Issues Of Quantum Secure Communication Theory

Quantum secure communication(QSC) is to encryption and decryption the message by the quantum key, which is to guarantee the security of the message. The QSC progresses by leaps and bounds. However, there are still many theoretical problems need to be further studied. Such as the strictly proof of the security of QSC, the relationship between efficiency and security of quantum cryptography protocol, the QSC protocol that uses the new quantum states, the network design of the QSC, and the large scale application of quantum cryptography. This paper focuses on the research of quantum key distribution and quantum secret sharing. The main results and innovations include the following aspects:With respect to the quantum key distribution, we propose two protocols. One is the quantum key distribution protocol using the Bell states. It‘s a simple, efficient and practical protocol. We established a mathematical model about the efficiency and security, and analysis their relationship by MATLAB. The other is the quantum key distribution using Fourier transform. It‘s a method that can produce quantum key greatly. The biggest feature of the protocol is that it is easy to be realized in quantum distributed computing, and performs efficiently on a quantum computer.In the aspect of quantum secret sharing, we also propose two protocols, respectively the multiparty quantum secret sharing based on entanglement swapping and quantum secret sharing using one-dimensional cluster states. The first is a(n, n)threshold case that it has n +1 participants. In order to improve the security and efficiency, Alice shares the secret key with the participants separately, only when she has finished communicating with one participant, then communicates with the next one. The protocol is safe that it cannot only prevent the external eavesdropper but also the internal cheater. In addition, the efficiency that is higher than many other protocols. The other case is to use the special graph states(cluster states) to design the protocol. The cluster states have the clear and special structure that can helpful to research and utilization. Therefore, it has very important value on the research of QSC using graph states.