Research On Quantum Key Distribution And Blind Quantum Computation

Quantum cryptography is a new discipline by using the physical properties of quantum mechanics to accomplish cryptographic tasks. Some quantum cryptographic issues can provide unconditional security. Quantum key distribution(QKD) is a method of generate keys, combining quantum mechanics with information theory. As a major research field of quantum cryptography, research on QKD and its security has great significance for secure communication.Quantum computation is a new computing model based on quantum mechanics, which is very important for cryptography, quantum secure communication and the realization of quantum computer. Blind quantum computing(BQC), as a research area of quantum computation, can allow a client with limited quantum power to delegate his quantum computation to a powerful server and still keep his own data private. It combines quantum computation and quantum cryptography. The importance of BQC can not be ignored.This thesis studies the theoretical aspects of quantum cryptography and quantum compuation, and then make a deep research on QKD and BQC separately. The main contributions of the thesis are as follows:(1) Summarize some typical QKD protocols, design a simulation process of BB84 protocol, and finish the emulational expriment on a classical computer.(2) Design and realize a QKD simulation model based on quantum entanglement. It can be used to simulate the QKD protocol on the ideal environment, the eavesdropping environment, and the noisy environment. The simulation results show the unconditional security of QKD protocol to some extent.(3) Propose a double-server BQC protocol by using the technique of entanglement swapping, which combines the proposed triple-server BQC protocol with single-server BQC protocol, can decrease the load of a single-server protocol and reduce the complexity of triple-server protocol.(4) Consider network’s variability which influences instable service of the quantum servers, and propose a flexible multiple-server BQC protocol that, can provide reliable and effective quantum compuation in networks.