Theoretical Research On Quantum Key Distribution Protocol

In today's society,the demand for the security of communications from individuals to the whole country is getting higher and higher.So far,the security of classical communication encryption methods depends on the complexity of algorithm instead of strict mathematics proof that will not guarantee absolute security of communication.With the rapid development of computer technology,many of the original secure encryption methods were vulnerable to more powerful algorithms and computers with powerful performance.In the last century in 80 s and 90 s,Bennett et al put forward the basic idea of quantum communication.Since then,quantum secure communication based on quantum key distribution has attracted more and more attention of scholars and countries.The basic laws of quantum mechanics ensures the absolute security of quantum key distribution in theory,which is the advantage that the classical communication does not have.In the past 30 years,researchers have made many theoretical and experimental achievements in the field of quantum key distribution.Firstly,we review the research background of quantum key distribution protocol,the development of quantum key distribution and the basic theoretical knowledge of quantum key distribution.We introduce in detail our research on quantum key distribution protocols.1.We explore the conventional three-intensity decoy state reference independent quantum key distribution protocol.At the same time,we take the light source errors and statistical fluctuations into consideration.The numerical simulation results show that the heralded single-photon source can achieve longer communication distance than the weak coherent source,but the weak coherent source can achieve higher key generation rates than the heralded single-photon source in short distance communication.2.We explore the reference independent quantum key distribution protocol under three different light sources such as the weak coherent source,the heralded single-photon source and the single-photon-added coherent state.Numerical simulation results show that the single-photon added-coherent states can achieve longer communication distance and higher key generation rates than the other two light sources.3.We study the new passive decoy state SARG04 protocol.Compared with the traditional active decoy state BB84 protocol and SARG04 protocol,numerical simulation results show that BB84 protocol has higher key generation rates at short communication distance while our new passive decoy SARG04 protocol can achieve longer communication distance.