基于态关联性不完美的诱骗态量子密钥分配

Decoy-State Quantum Key Distribution Based on State-Dependent Imperfections

本文提出了态关联性不完美条件下诱骗态量子密钥分配(QKD)的安全性理论分析模型.借助于QKD的保密放大分析方法,采用实际QKD系统广泛使用的诱骗态编码方案,使相位误码的估计更加准确,进而给出了态关联性不完美条件下诱骗态QKD的最终安全密钥生成率的表达式,刻画了密钥生成率与态关联性不完美、探测器性能和密钥传输距离之间的关系.数值模拟表明,诱骗态QKD的最终安全密钥生成率对态关联性不完美的容忍程度,随着密钥传输距离的增大而逐渐减小,随着探测器探测性能的提升而逐渐增大,因而验证了所给表达式的正确性.

This paper proposes models for analyzing the security of decoy-state quantum key dislribution （QKD） with state dependent imperfections. With the privacy amplification method of QKD＇ s post-processing techniques, we introduce the decoy-state method used widely in QKD system to estimate the phase error rate more accurately than the case without decoy-state method. Based on this, we obtain the formula of secret key generation rates for decoy-state QKD with state-dependent imperfections, and characterize the relationship among key generation rates, state dependent parameter, detection efficiency and transmission distance. Numerical simulations indicate that the secure key generation rates＇ tolerance to state-dependent imperfections decreases with the growing distance,but increases with the improving detection efficiency, which,to some extent,show the validity of the formula we obtain.