Tight finite-key analysis for passive decoy-state quantum key distribution under general attacks

摘要

For quantum key distribution (QKD) using spontaneousparametric-down-conversion sources (SPDCSs), the passive decoy-state protocolhas been proved to be efficiently close to the theoretical limit of an infinitedecoy-state protocol. In this paper, we apply a tight finite-key analysis forthe passive decoy-state QKD using SPDCSs. Combining the security bound based onthe uncertainty principle with the passive decoy-state protocol, a concise andstringent formula for calculating the key generation rate for QKD using SPDCSsis presented. The simulation shows that the secure distance under our formulacan reach up to 182 km when the number of sifted data is $10^{10}$. Our resultsalso indicate that, under the same deviation of statistical fluctuation due tofinite-size effects, the passive decoy-state QKD with SPDCSs can perform aswell as the active decoy-state QKD with a weak coherent source.