中文摘要：

量钥匙分发(QKD ) 的安全性质系统用圈套状态与实际轻来源一起被分析方法。有传播距离的变化的安全的关键率在理想的系统，无限的轻来源系统， untrusted 光来源和被动系统的条件下面被计算。系统的安全特征上的传播率的变化的影响被讨论。我们的数字模拟结果为实际 QKD 实验提供一本有用参考书。

英文摘要：

The security properties of quantum key distribution （QKD） system are analyzed with the practical light source using decoy state method. The secure key rate with the change of transmission distance is computed under the condition of ideal system, infinite light source system, untrusted light source and passive system. The influence of the fluctuation of transmission rate on the security characteristics of the system is discussed. Our numerical simulation results offer a useful reference for the practical QKD experiment.