Abstract: Due to the limitation of expensive physical devices and experiment conditions, the simulation of Quantum Key Distribution（QKD） with classical computers has been an alternative method to understand abstract quantum cryptographic protocols. This paper designs the simulation processes of QKD on a classical computer，taking E91 protocol as an example, and analyzes the simulation results in three cases: the channel is ideal，the channel is noisy, and the eavesdropper exists. The security of protocol is also shown.

Key words: quantum cryptography, quantum key distribution, computer simulation

摘要： 由于受物理资源和实验条件的限制，在经典计算机上对量子密钥分配（QKD）仿真，为研究者提供一种手段以便更好地掌握这类抽象协议。对以纠缠态为基础的E91协议的量子密钥分配过程进行仿真，重点对比分析了理想环境、有噪环境以及窃听环境下的仿真结果，并验证该量子密钥分配协议的安全性。

关键词: 量子密码, 量子密钥分配, 计算机仿真