正算子估值测量量子密钥分配方案及安全性分析

为探索一种直接应用正算子估值测量进行量子密钥分配的最佳方案,利用正算子估值测量对两个非正交量子态的可靠识别,提出了一种使用该测量法直接进行量子密钥分配的方案.分析了无噪信道环境下具有最佳安全性兼具较高效率、两非正交量子态间最佳夹角的取值,及在此情况下窃听者造成的错误率门限.计算表明,本方案通信双方密钥的分配效率可达50%,对窃听者的检测率达6.25%,仅需3次密钥协商过程,达到或优于主流经典量子密钥分配协议各项指标,有一定实际应用价值.

Study of QKD Scheme Based on POVM and Security Analysis

An optimal scheme of quantum key distribution（QKD） based on positive operation valued measurement（POVM） is put forward,in which POVM can distinguish the two non-orthogonal quantum states reliably.The optimal angle of the two non-orthogonal quantam states modulated by the communication organiger and the error rate made by an eavesdropper are analyzed,which suggests that in a non-noise channel,the scheme is of best security and high efficiency.The calculation shows that the QKD efficieny of the two sides gets to 50%,the probability of detecting eavesdroppers is 6.25%,and 3 cycles to accomplish the QKD process are needed.The scheme is superior to the indexes of the mainstream classic QKD protocols,so itis of thus having practical value.