非对称信道传输效率的测量设备无关量子密钥分配研究

测量设备无关量子密钥分配方案可以移除所有的探测器侧信道漏洞,通过结合诱骗态方案可以生成无条件安全的密钥.本文研究了非对称信道传输效率下三强度诱骗态测量设备无关量子密钥分配系统的密钥生成率与信道传输损耗的关系,比较了对称信道传输效率和非对称信道传输效率下的距离比率对单边传输效率、单光子误码率和量子密钥生成率的影响,仿真结果表明随着信道不匹配度逐渐增加,可容忍信道传输损耗由对称信道情形下的62 dB分别降至38 dB(距离比率为0.5)和17 dB(距离比率为0.1),能够安全提取密钥的可容忍传输损耗下降较快,密钥生成率的安全传输距离也随之降低.实验中可以采取调节信号光强度的方式提高非对称传输效率下测量设备无关量子密钥分配系统的密钥生成率,为实用的量子密钥分配实验提供了重要的理论参数.

Analysis of measurement device independent quantum key distribution with an asymmetric channel transmittance efficiency

Measurement-device-independent quantum key distribution is immune from all the detection attacks, thus when it is combined with the decoy state method, the final key is unconditional secure. In this paper, the performance of three-intensity decoy state measurement-device-independent quantum key distribution at an asymmetric channel transmittance efficiency is considered and compared with each other at the symmetric choice scenario. Simulation result shows that the key rate at the symmetric scenario can tolerate 62 dB channel loss, otherwise when the distance ratio changes, the tolerated channel loss will decrease to 37 dB and 19 dB. A method to choose the optimal intensity is proposed for asymmetric channel transmittance regardless of distance ratio, which can be easily adapted to practical experimental settings.