Parameter Optimization And Performance Study Of Practical Quantum Communication Network

Quantum key distribution is a key technology for quantum communication.It perfectly combines quantum theory and information theory,which can be said to have absolute theoretical security.However,due to flawed experimental devices,such as imperfect sources and low efficiency single photon detectors,there is a huge gap between the practical application and theoretical expectation of quantum key distribution.These gaps are often manifested in the performance of communication systems,such as key generation rates and maximum secure communication distances.The gaps will introduce some security loopholes,which could lead to many targeted attacks,these attacks may greatly threaten the security of the communication process.Many efforts have been made for the gaps.Among them,the measurement device-independent quantum key distribution(MDI-QKD),proposed by Lo et al,can solve most vulnerabilities on the measurement side,thereby preventing attacks on the measurement side.MDI-QKD has therefore become a highly secure,practically deployable quantum key distribution system.Based on this,this thesis makes further research on the measurement device independent quantum key distribution protocols.In this paper,we first introduce the theoretical background of this article and report the latest research progress of quantum communication.Then made a summary of the development of quantum key distribution protocols.After that,we introduce in detail the theory and protocol of measuring device-independent quantum key distribution in asymptotic case and finite data set,and give the key rate formulas in different cases.Under the asymptotic condition,our results show a linear relationship between the channel transmittances and the optimal intensities of the signal and decoy states under asymmetric channels.In the finite data set,we introduce a standard error analysis method to analyze the impact of statistical fluctuations on system performance and parameter optimization results under the effect of finite data length.Then we introduced a multi-dimensional-coding MDI-QKD protocol,discussed the characteristics of the protocol and compared it with the original-coding MDI-QKD protocol,and our results further verified the feasibility of the protocol.Our analysis results can provide valuable theoretical references for the experiments and applications of MDI-QKD.