Analysis Of Key Conciliation Algrithm And Detecting Technology In QKD System

Cryptography has a long history, which has become an applied science in recent years. Cryptography is used in many fields in modern society, such as military affairs, national security, email and bank account. Modern cryptography can be divided into two categories, symmetric and asymmetric system. The security of asymmetric system is based on the computational complexity. As the rapid progress in computer science, especially the arising of the concept of quantum computer, the security of asymmetric is challenged severely. The major problem in symmetric cryptographic system is how to distribute keys between the legitimate users.Quantum cryptography is a combination of quantum mechanics and cryptology. The security of quantum cryptosystems is guaranteed by the fundamental laws of quantum mechanics:the uncertainty principle and the non-cloning theorem. Using these secure keys generated by quantum key distribution and one time one pad algorithm we can achieve absolutely secure communications.The dilemma of quantum key distribution is low generation rate of secure keys. In quantum key distribution systems, error reconciliation algorithm used in post-processing procedures has great influence on the key generation rate. The most popular error conciliation algorithms is binary algrithm, Cascade algrithm and hamming algrithm. These three algrithms have the strengths and weaknesses. This paper discusses the performance of these three algrithms and implements the hamming error conciliation algrithm in project. Detecting technology is one of the most important technologies in quantum key distribution system, and has great influence on key generation rate. The researches on detecting are mainly focus on the efficiency of detector, this paper introduces the dual detector theory raised by Bing Qi and applies it to BBM92 protocol for the first time. We analyse the performance of this application by simulation result which shows the application of dual detectors in BBM92 protocol can raise the key generation rate and secure communication distance. At last, the author introduces the characteristics of quantum key distribution network and proposes a new efficient and practical quantum key distribution network model.