Research Of Related Problems Of Quantum Key Distribution And Authentication

As the development of information technology, all parts of our society demand for information security, and it draws international attention. Because information security not only influences national politics security, economy security, military security and stabilization of the society, but also has effects on the quality of digital life of every person in the society.Quantum secure communication is a new research area based on classical information theory and quantum mechanics theory. Quantum cryptography can be used in many areas of information protection such as obtaining a secret key, encrypting data, hiding information, identity authentication, confirmation of information and so on.The purposes of this paper are focused on theoretic researches of quantum key distribution and the security analysis of it. A new scheme of quantum security communication is proposed and an experiment of a quantum identity authentication scheme has been completed.In theory, we designed a continuous variable quantum security communication scheme based on Gaussian modulation and EPR entanglement pairs. Its security can be guaranteed by principles of quantum mechanics. The scheme overcomes some shortcomings of quantum key distribution schemes based on discrete modulation by improving the key distribution efficiency. Besides, the scheme can be also used in quantum direct communication. Thus, it is more flexible and practical.In experiment, we presented a realizable quantum identity authentication scheme based on modulation of photons’polarization states and completed the experimental demonstration of this scheme in optical fiber system. It has been proved that the scheme is feasible. During the experiment, we studied and mastered some key technologies, such as quantum signals’generation, modulation, detection, and accessorial circuit module, control module, software module, and etc. We also analyzed the performance of this scheme. It is extensible. According to its shortages, we gave some improved methods and made a favorable foundation for coming researches.