Passive scheme with a photon-number-resolving detector for decoy-state quantum key distribution with an untrusted source
Bingjie Xu, Xiang Peng, Hong Mei Guo
Abstract
A passive scheme with a photon-number-resolving detector and a beam splitter which are used to monitor the statistical characteristics of photon source, is proposed to verify the security of three-intensity decoy-state quantum key distribution system with an untrusted source. The practical issues due to statistical fluctuation and detection noise are analyzed. The simulation results show that the scheme can work efficiently when the data size $N\ge10^{8}$ and the dark count rate of the detector is below 0.5 counts/pulse, which are realizable by current techniques. We also give an experimental example of PNR detector which is easily realized by a variable optical attenuator combined with a practical threshold detector.