基于散粒噪声方差实时监测的连续变量量子密钥分发系统的设计与实现  

The design and realization of continuous-variable quantum key distribution system based on real-time shot noise variance monitoring

作　　者：曹正文[1,2] 张爽浩 冯晓毅[2] 赵光[1] 柴庚 李东伟[1] Cao Zheng-Wen Zhang Shuang-Hao Chai Geng Feng Xiao-Yi Li Dong-Wei Zhao Guang(School of Information Science and Technology, Northwest University, Xi＇an 710127, China School of Electronics and Information, Northwestern Polytechnical University, Xi＇an 710072, China Received 15 August 2016, revised manuscript received 2 November 2016 ,)

机构地区：[1]西北大学信息科学与技术学院,西安710127 [2]西北工业大学电子信息学院,西安710072

出　　处：《物理学报》2017年第2期39-45,共7页Acta Physica Sinica

基　　金：陕西省科技厅自然科学基金(批准号:2013JM8036);"十二五""211工程"创新人才培养项目(批准号:YZZ15100)资助的课题~~

摘　　要：为了有效抵御窃听者对本振光的攻击,提高连续变量量子密钥分发(continuous-variable quantum key distribution,CVQKD)系统的安全性,提出了一种基于散粒噪声方差实时监测的CVQKD系统.该系统采用散粒噪声方差标定技术,在原有的CVQKD系统中加入散粒噪声方差实时监测模块,通过本振光强和散粒噪声方差的线性关系评估出实时的散粒噪声方差,再计算系统准确实时的密钥率来判断当前系统是否处于安全状态.实验上也表明了该系统能够有效抵御Eve对本振光的攻击,提高CVQKD系统的安全性.In the safety assessment of the actual CVQKD（continuous-variable quantum key distribution） system, the preparation measurement model is generally equivalent to the entanglement-based model, whose major drawback is that the shot noise variance is treated as a constant. As the attacks on the LO（local oscillator） from the Eve, the shot noise variance will change with LO. And in the process of safety analysis based on the shot noise variance calibration technology, there are loopholes in which the shot noise variance for calculating secret key rate is obtained by the linear relationship between the shot noise variance and the LO before distributing the quantum key. However, the shot noise variance is not accurate nor real-time. In the security analysis of system, all the noise parameters of the system are normalized to the shot noise variance. The Eve can reduce the shot noise variance by controlling the strength of LO, thus actual excess noise of system will increase. But legal communicating parties are still normalized based on previous larger shot noise variance, so that the excess noise of system is substantially underestimated. As a consequence, the Eve can obtain secret key information without attracting the attention of legal communicating parties by adopting some attacks,such as intercept-resend attack. Thus it is an essential factor for ensuring the system security to evaluate real-time shot noise variance accurately. In order to effectively resist the above mentioned attacks on the LO from the Eve, a scheme of CVQKD system based on real-time shot noise variance monitoring is presented to improve the security of CVQKD system. The shot noise variance calibration technology is adopted in this system. By adding the real-time shot noise variance monitoring modules to the primary CVQKD system, the real-time shot noise variance is assessed by the linear relationship between the shot noise variance and the LO. In the hardware system, independent clocks are adopted.Sampling in peak algorithm is applied to so

关 键 词：连续变量量子密钥分发系统 散粒噪声方差标度技术 本振光 实时散粒噪声方差 

分 类 号：O413[理学—理论物理] TN918.4[理学—物理]