Key Technology Research Of The Networked Quantum Key Distribution System

Since the first protocol of quantum key distribution was proposed in 1984,quantum communication,especially quantum key distribution has gained outstanding achievements both in theory and experiment.More and more government,enterprises and research institutions are interested in QKD because it can guarantee unconditional security in theory.Practical application of the quantum key distribution system is one of the highlights of the current research in the field of quantum information,and it’s more and more evident with the rapid development of information technology,quantum secure communication network is the trend of quantum communication.Measurement device independent quantum key distribution system is the most close to the actual application of the system.In this paper,we firstly introduce the development of the quantum key distribution and list some achievements of pear to pear QKD and QKD network,we analysis the mathematical model of source,channel and detector of the quantum key distribution system based on the BB84 protocol,combine with the decoy method and GLLP formula,talk about the performance of practical measurement device independent quantum key distribution system and combine with some latest improved schemes at home and abroad.Then we get the lower bounds of yield and upper bounds of error rate by parameter optimization,theoretical analysis the main factors influencing the secure key generation rate in asymptotic case,provide important reference for the related experiments.For practical setup,we firstly study various error source due to the imperfection factors,how background count rate and polarization misalignment affect our system,and get the relationship between secure key rate and transmission distance;Finally we consider the situation where Alice and Bob send different intensity of signal state and the performance of quantum communication network system in asymmetric case,These work provide important theoretical reference to the study of practical quantum communication network.