Research On Practical Phase-Matching Quantum Key Distribution Protocol

Quantum Key Distribution(QKD),as an important branch of quantum communication,breaks through the security of traditional key distribution based on computational complexity and achieves absolute security guaranteed by the fundamental principles of quantum mechanics.The Twin-field Quantum Key Distribution(TF-QKD)protocol not only inherits the security advantages of the Measurement-Device-Independent Quantum Key Distribution(MDI-QKD)protocol,removing all detector side attacks,but also breaks the fundamental rate-loss relationship without quantum repeaters.It has achieved a huge leap in terms of transmission distance and secure key rate.The phase-matching quantum key distribution(PM-QKD)protocol,a variant of TF-QKD protocol,removes the requirement of phase-locking by using the phase post-compensation technique,and exhibit a better performance in QKD process.The thesis focuses on the study of PM-QKD protocol with different laser sources and the security of PM-QKD protocol under non-ideal source.The main research works and results are as follows:(1)Phase-Matching Quantum Key Distribution Based On Heralded Pair-Coherent Source(HPCS-PM-QKD)is proposed.The relatively less single-photon component of the most frequently used weak coherent source(WCS)makes it unable to meet the high-performance requirements of communication,and the HPCS can compensate for this deficiency.In this thesis,we propose a fourintensity decoy-state PM-QKD protocol based on HPCS to improve the secure key rate and the practicality.Through simulation and comparison,it is shown that the secure key rate of the proposed scheme is about an order of magnitude higher than that of four-intensity decoy-state PM-QKD protocol based on WCS.Meanwhile,the maximum transmission distance is increased by more than100 km.In addition,the performance of four-intensity decoy-state HPCS-PM-QKD protocol has been greatly improved,in comparison with the better performance protocol known as ‘new PM-QKD’.Therefore,it is shown the proposed protocol has the characteristics of higher secure key rate and larger transmission distance applicable to practical communication.(2)Passive Light Source Monitoring(PLSM)for Phase-Matching Quantum Key Distribution(PLSM-PM-QKD)is discussed.Usually,in most QKD protocols,the light source is considered to be reliable and has a fixed photon number distribution,which is unrealistic in practical.The active light source monitoring(ALSM)method may introduce new security holes due to the imperfection of the attenuation devices,resulting in additional modulation errors.Therefore,a PLSM-PM-QKD protocol is discussed,where the probability distribution of non-ideal light sources is determined through the response of the local detectors.The simulation results show that when non-ideal light sources are considered and the modulation errors are added,the performance of PLSM-PM-QKD protocol is significantly better than that of ALSM-PM-QKD protocol.In other cases,the key rate and maximum transmission distance of PLSM-PM-QKD protocol are almost the same as those of ALSM-PM-QKD protocol,close to those of PM-QKD protocol.