Zhao Wei, Guo Ying, Zhang Ling, Huang Duan
Opt Express. 2019 Feb 4;27(3):1838-1853. doi: 10.1364/OE.27.001838.
Excess noise induced by the phase drifts is a serious impairment for the continuous-variable quantum key distribution with locally generated local oscillator scheme, which is recently proposed to avoid the side channel attacks due to the transmitted local oscillator. Theoretical and experimental studies on the phase estimation have been widely reported, while two frequency-locked laser sources are indispensable to achieve quantum coherent detection. Moreover, the self-referenced phase estimation scheme requires to propagate the strong reference pulse through optical fiber, which opens a security loophole through the manipulation of the reference pulse amplitude. Based on the theoretical security and Bayes' theorem, we propose a phase estimation protocol, which does not require propagating the strong reference pulse for performing phase estimation. Compared to the other related work, the protocol can avoid the security problem caused by strong reference pulse. Moreover, this algorithm is an iterative progress for each of experiment to obtain the phase estimation and its uncertainty. We hope the proposed scheme could further promote the performance of continuous-variable quantum key distribution.
由相位漂移引起的过量噪声对于采用本地生成本地振荡器方案的连续变量量子密钥分发来说是一种严重的损伤，该方案是最近为避免因传输本地振荡器而产生的侧信道攻击而提出的。关于相位估计的理论和实验研究已有广泛报道，而实现量子相干检测需要两个锁频激光源。此外，自参考相位估计方案要求强参考脉冲通过光纤传输，这通过操纵参考脉冲幅度打开了一个安全漏洞。基于理论安全性和贝叶斯定理，我们提出了一种相位估计协议，该协议在进行相位估计时不需要传输强参考脉冲。与其他相关工作相比，该协议可以避免由强参考脉冲引起的安全问题。此外，该算法对于每次实验来说是一个迭代过程，以获得相位估计及其不确定性。我们希望所提出的方案能够进一步提升连续变量量子密钥分发的性能。
