Li Huasheng, Wang Chao, Huang Peng, Huang Duan, Wang Tao, Zeng Guihua
Opt Express. 2016 Sep 5;24(18):20481-93. doi: 10.1364/OE.24.020481.
In a practical continuous-variable quantum key distribution system, finite sampling bandwidth of the employed analog-to-digital converter at the receiver's side may lead to inaccurate results of pulse peak sampling. Then, errors in the parameters estimation resulted. Subsequently, the system performance decreases and security loopholes are exposed to eavesdroppers. In this paper, we propose a novel data acquisition scheme which consists of two parts, i.e., a dynamic delay adjusting module and a statistical power feedback-control algorithm. The proposed scheme may improve dramatically the data acquisition precision of pulse peak sampling and remove the finite sampling bandwidth effects. Moreover, the optimal peak sampling position of a pulse signal can be dynamically calibrated through monitoring the change of the statistical power of the sampled data in the proposed scheme. This helps to resist against some practical attacks, such as the well-known local oscillator calibration attack.
在实际的连续变量量子密钥分发系统中，接收机端所采用的模数转换器的有限采样带宽可能会导致脉冲峰值采样结果不准确。进而，导致参数估计出现误差。随后，系统性能下降，安全漏洞暴露给窃听者。在本文中，我们提出了一种新颖的数据采集方案，该方案由两部分组成，即动态延迟调整模块和统计功率反馈控制算法。所提出的方案可以显著提高脉冲峰值采样的数据采集精度，并消除有限采样带宽的影响。此外，在所提出的方案中，可以通过监测采样数据统计功率的变化来动态校准脉冲信号的最佳峰值采样位置。这有助于抵御一些实际攻击，例如著名的本地振荡器校准攻击。
