与经典网络相比,QKD(Quantum Key Distribution)网络利用量子密钥分发技术能在公共网络中为数据通信提供无条件安全的密钥。欧洲Secoqc(Secure Communication Based on Quantum Cryptography)项目研究可大范围应用于绝对安全性通信网络...与经典网络相比,QKD(Quantum Key Distribution)网络利用量子密钥分发技术能在公共网络中为数据通信提供无条件安全的密钥。欧洲Secoqc(Secure Communication Based on Quantum Cryptography)项目研究可大范围应用于绝对安全性通信网络。详细介绍Secoqc QKD网络的结构及协议,及其在维也纳的实验网络。展开更多
In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization n...In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel,but also reduce the noise introduced by phase interference.However,arbitrary continuous modulation can not be carried out in the past polarization coding,resulting in that the signal state can not obtain arbitrary continuous value in Poincare space,and the security analysis of CV-QKD using polarized coherent-states in free space is not complete.Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller.In particular,in terms of the main influence factors in the free-space channel,we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate.In addition,the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather.Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather.The protocol fails when visibility is less than 1 km.At the same time,the wavelength can affect the performance of the proposed scheme.Specifically,under foggy weather,the longer the wavelength,the smaller the attenuation coefficient,and the better the transmission performance.Our proposed scheme can expand the modulation range of signal state,and supplement the security research of the scheme in the free-space channel,thus can provide theoretical support for subsequent experiments.展开更多
文摘与经典网络相比,QKD(Quantum Key Distribution)网络利用量子密钥分发技术能在公共网络中为数据通信提供无条件安全的密钥。欧洲Secoqc(Secure Communication Based on Quantum Cryptography)项目研究可大范围应用于绝对安全性通信网络。详细介绍Secoqc QKD网络的结构及协议,及其在维也纳的实验网络。
基金the Key Program of the National Natural Science Foundation of China(Grant No.61531003)the National Natural Science Foundation of China(Grant No.62001041)+1 种基金China Postdoctoral Science Foundation(Grant No.2020TQ0016)the Fund of State Key Laboratory of Information Photonics and Optical Communications.
文摘In free space channel,continuous-variable quantum key distribution(CV-QKD)using polarized coherent-states can not only make the signal state more stable and less susceptible to interference based on the polarization non-sensitive of the free-space channel,but also reduce the noise introduced by phase interference.However,arbitrary continuous modulation can not be carried out in the past polarization coding,resulting in that the signal state can not obtain arbitrary continuous value in Poincare space,and the security analysis of CV-QKD using polarized coherent-states in free space is not complete.Here we propose a new modulation method to extend the modulation range of signal states with an optical-fiber-based polarization controller.In particular,in terms of the main influence factors in the free-space channel,we utilize the beam extinction and elliptical model when considering the transmittance and adopt the formulation of secret key rate.In addition,the performance of the proposed scheme under foggy weather is also taken into consideration to reveal the influence of severe weather.Numerical simulation shows that the proposed scheme is seriously affected by attenuation under foggy weather.The protocol fails when visibility is less than 1 km.At the same time,the wavelength can affect the performance of the proposed scheme.Specifically,under foggy weather,the longer the wavelength,the smaller the attenuation coefficient,and the better the transmission performance.Our proposed scheme can expand the modulation range of signal state,and supplement the security research of the scheme in the free-space channel,thus can provide theoretical support for subsequent experiments.
