信息网络安全

信息网络安全 ›› 2025, Vol. 25 ›› Issue (5): 806-816.doi: 10.3969/j.issn.1671-1122.2025.05.012

• 理论研究 • 上一篇    下一篇

基于离散极化调制与离散有界探测的CVQKD安全性分析

杨雯, 王天一(), 杜俊男, 王成   

  1. 贵州大学大数据与信息工程学院，贵阳 550025
  • 收稿日期:2025-02-04 出版日期:2025-05-10 发布日期:2025-06-10
  • 通讯作者: 王天一 tywang@gzu.edu.cn
  • 作者简介:杨雯（2000—），女，山东，硕士研究生，主要研究方向为量子密钥分发、人工智能|王天一（1989—），男，辽宁，副教授，博士，主要研究方向为量子通信、图像处理、计算机视觉|杜俊男（2000—），男，贵州，硕士研究生，主要研究方向为深度学习、图像处理|王成（1999—），男，贵州，硕士研究生，主要研究方向为深度学习、图像处理
  • 基金资助:
    国家自然科学基金(62361009);贵州省科技计划(黔科合基础-ZK[2021]一般304)

Security Analysis of Continuous-Variable Quantum Key Distribution Based on Discretized Polar Modulation and Coarse-Grained Measurement with Finite Range

YANG Wen, WANG Tianyi(), DU Junnan, WANG Cheng   

  1. School of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
  • Received:2025-02-04 Online:2025-05-10 Published:2025-06-10

RichHTML

19

PDF (PC)

21

摘要：

连续变量量子密钥分发理论上无条件的安全性已被证明，但受实验系统中器件非理想特性的影响，理想的连续分布量子信号会发生退化，进而引发系统性能下降。为弥合连续变量量子密钥分发理论与实践之间的差距，文章考虑发送端调制器和接收端探测器的有限分辨率对系统性能的影响，构建一个基于离散极化调制与离散有界探测的协议模型，并评估该模型下的参数估计的偏差特性及其对安全码率的影响。数值仿真结果表明，发送端和接收端离散效应的耦合作用会使得过量噪声的估计值产生偏差，导致系统安全码率先增后减，最终急剧下滑。当量子信道的传输率位于0.2~0.6时，过量噪声的估计偏差会导致系统安全码率被严重低估，进而制约系统的最大传输距离。零差探测器的有限量程效应是诱发过量噪声估计偏差的最主要因素，这可以通过调节发送端的调制方差来进行有效补偿。

关键词: 量子密钥分发, 连续变量, 离散极化调制, 离散有界探测

Abstract:

The unconditional security of continuous-variable quantum key distribution has been demonstrated under theoretical conditions. However, due to the non-ideal experimental devices in the experimental system, the ideal continuously distributed quantum signals are degraded, which in turn triggers the degradation of the system performance. To bridge the gap between the theory and practice of continuous-variable quantum key distribution, the article considering the impacts of the limited resolution of the modulator at the transmitting end and the detector at the receiving end on the system performance, proposed a model based on discretized polar modulation and coarse-grained measurement with finite range. It also evaluated the bias characteristics of parameter estimation under this model and its impact on the security key rate. Numerical results show that the coupling effect of the discrete effects at the transmitter and the receiver causes deviations in the estimated value of excess noise, leading to an initial increase followed by a decrease and ultimately a sharp decline in the system security key rate. When the channel transmission is between 0.2 and 0.6, the estimation deviation of excess noise can lead to a severe underestimation of the system security key rate, which in turn restricts the maximum transmission distance of the system. The finite range effect of the homodyne detector is the most significant factor inducing the estimation deviation of excess noise, which can be effectively compensated for by adjusting the modulation variance.

Key words: quantum key distribution, continuous-variable, discretized polar modulation, coarse-grained measurement with finite range

中图分类号: