Research And Design On Key Agreement Protocols Based On Physical Noise

With the rapid development of optical fiber communication technology,optical fiber communication system and network have become the most important communication facilities.How to ensure the security of optical fiber communication has become an important problem.As a widely used method to ensure the security of optical fiber communication,the classical encryption technology faces the threat of being cracked by the quantum computers.In recent years,as a necessary supplement to classical encryption technology,the physical layer security technology has become an important means to ensure the security of optical fiber communication and has formed two technical directions of encrypted transmission and key agreement.In the key-based security technology,the security of information depends on the security of key,therefore key agreement technology has a very important impact on the security of optical fiber communications.Focusing on how to ensure the security of optical fiber communication by using physical noise,the author explores the possibility of key agreement based on physical noise of optical fiber communication system.Focusing on the problem of limited key generation rate,the author studies key agreement scheme based on the intensity modulation quantum noise stream encryption mechanism as well as key agreement scheme based on phase noise masking.In addition,encrypted transmission scheme based on phase noise masking is also studied.The main work and research achievements of this article are as follows:(1)Based on the agreement characteristics of shot noise and ASE noise which are used to mask signals in quantum noise stream encryption technology,the signal change process of intensity modulation quantum noise stream encryption mechanism is modeled and analyzed.The influence of two factors on the error rate of the intensity modulation quantum noise stream encryption mechanism are analyzed.These two factors are the noise and the state base difference of the two communication parties.Besides,the security analysis of the key agreement scheme based on feature extraction of optical fiber channel is performed,and the security of the bit error rate result obtained by the double-ended loopback measurement is proved.(2)Utilizing the bit error rate characteristics of the intensity modulation quantum noise stream encryption mechanism,a key agreement scheme based on surviving symbol exchange under the intensity modulation quantum noise stream encryption mechanism is proposed.This scheme achieves key agreement by utilizing the difference in the bit error rate of same-base symbol and different-base symbol.Simulation results show that the scheme can obtain an initial key with a consistency rate higher than 98%and achieve a key generation rate of 0.12%.Besides,the key also has good randomness and security.(3)Based on the characteristics of laser phase noise in high-speed optical fiber communication system,a key agreement scheme and an encrypted transmission scheme based on phase noise masking in single-carrier coherent optical communication system are proposed respectively.A single-carrier coherent optical transmission simulation model is built by Matlab.Simulation results show that the proposed key agreement scheme can achieve a key consistency rate of 98.5%and a key generation rate of 0.12%,indicating that the proposed scheme has good key consistency rate and key generation rate.The scheme also has good key randomness and security.In addition,simulation results of the proposed encryption transmission scheme show that the bit error rate of the legal receiver is less than 1E-4,while the error rate of the eavesdropper Eve is about 0.5,indicating that the scheme has good transmission performance and security.