一维高斯调制连续变量量子密钥分发现实源强度误差的影响  

Influence of source intensity errors in unidimensional Gaussian modulation continuous-variable quantum key distribution

作　　者：王普 白增亮 常利伟[1] WANG Pu;BAI Zengliang;CHANG Liwei(School of Information,Shanxi University of Finance and Economics,Taiyuan 030006,China)

机构地区：[1]山西财经大学信息学院,太原030006

出　　处：《物理学报》2025年第9期56-66,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62305198);山西省自然科学基金(批准号:202303021212168,202103021224290)资助的课题.

摘　　要：本文深入地研究了一维高斯调制连续变量量子密钥分发系统在源强度误差下的现实安全性和性能表现.详细地分析了源强度误差对协议参数估计过程的影响机制,并基于发送端的三种现实假设,提出相应数据优化方案,以减轻源强度误差的负面影响.同时,综合考虑了源强度误差及有限码长效应,以保障系统的现实安全性.研究结果表明,源强度误差不可忽视,对于显著的强度波动,系统的最大传输距离将减少约20 km.因此,在协议的实际实施过程中,必须充分考虑源强度误差的影响,并采取相应的措施来减少或消除这些误差.本研究为现实条件下实施一维高斯调制连续变量量子密钥分发提供了理论依据,为构建高效、低成本、小型化的量子通信网络探索了新方向.Unidimensional Gaussian modulation continuous-variable quantum key distribution(UD CV-QKD)uses only one modulator to encode information.The UD CV-QKD has the advantages of low implementation cost and low random number consumption,making it attractive for the construction of future miniaturized and lowcost large-scale quantum communication networks.However,in the actual application of the protocol,the intensity fluctuation of the source pulsed light,device defects,and external environmental interference maybe lead to the generation of source intensity errors,thereby affecting the realistic security and performance of the protocol.To solve these problems,the security and performance of UD CV-QKD are studied in depth under source intensity errors in this work.The mechanism of source intensity errors influencing the protocol parameter estimation process is analyzed.To make it possible that the protocol can operate stably under various realistic conditions and ensure communication security,three practical assumptions about the sender’s abilities are made in this work,and corresponding data optimization processing schemes for these assumptions are proposed to reduce the negative influence of source intensity errors.Additionally,both source errors and finite-size effect are comprehensively considered to ensure the realistic security of the system.The simulation results indicate that the source intensity errors cannot be neglected and the maximum transmission distance of the system will be reduced by approximately 20 km for significant intensity fluctuations.Therefore,in the practical implementation of the protocol,the influence of source intensity errors must be fully considered,and the corresponding countermeasures should be taken to reduce or even eliminate these errors.This study provides theoretical guidance for securely implementing the UD CV-QKD in real-world environments.

关 键 词：连续变量量子密钥分发 一维调制 源误差 现实安全性 

分 类 号：O413[理学—理论物理]