基于BB84协议的量子密钥分发安全门限研究

摘要

本文分析了实际量子密钥分发过程中,量子态可能受到的各种影响因素;建立了相应的信道模型;推得了非理想信道BB84协议判别窃听的安全门限公式.通过计算与仿真,证明该公式用于估计BB84协议的安全通信门限更加准确,判断量子密钥分发过程中是否存在窃听更为有效,同时具有提高通信安全性和密钥分发效率的优点.%Quantum state in the channel is affected by several factors, which will bring detection error and make secure threshold of quantum distribution protocol unable to judge whether eavesdropping exists. We analyze the factors in real quantum channel, which affects the quantum state, develop a channel model, and derive a judging eavesdrop secure threshold formula of BB84 protocol based on an imperfect channel. Through calculating and simulating, the formula is proved to be more accurate to estimate the secure threshold of the BB84 protocol and more effective to judge eavesdropping. Meanwhile, this method can improve the security and the efficiency of key distribution.