Optical Fiber Channel Characteristics Based Physical Layer Secure Technologies Research Of Passive Optical Network

Due to the advantages of high speed,large bandwidth and long transmission distance,optical fiber communications are widely applied in personal,commercial,and military communications.Meanwhile,with the advent of 5G and concepts of interconnections and intelligence,the capacity of optical network is explosively growing.Therefore,to meet the ever-increasing demand of high-speed,reliable transmission with minimum cost of next generation optical network,the passive optical network(PON)has been widely deployed as a new optical access technology to connect users and access networks.However,the network attacks pose more serious threats to PON because of its special broadcasting nature and topological structure.Therefore,it is very important to propose some physical layer based secure technologies that can effectively resist the network attacks in PON.The main research content and innovation of this paper are as follows:(1)Aiming at the problems of low key generation rate(KGR),short transmission distance,separated plaintext and key transmission,small key space,and static key in the schemes of secure key generation and distribution schemes based on endogenous security,a secure optical transmission system based on neural network and channel characteristic estimation is proposed.By training the neural networks(NNs)offline locally and transmitting the pseudo-keys during the communication,the proposed system can transmit the plaintext together with key,transforming the key dynamically.Moreover,because the channel characteristics of the legal and illegal parties are not completely identical,the illegal eavesdropper cannot acquire the same NN as the legal parties.Simulation results prove the feasibility of the system with the transmission rate of 100 Gbps and transmission distance of 100 km,verifying the high security and randomness of the generated key.In addition,if the plaintext and key have equivalent code length during communicating between the legal parties,the 50 Gbps KGR will be realized in theory.(2)Aiming at the problems of high complexity of traditional authentication protocols and static fingerprint of existing physical layer based authentication methods,an identity authentication method based on adjustable channel characteristic fingerprint and NNs is proposed.By secretly negotiating with each legal optical network unit(ONU)about the length of the local fiber used by each legal ONU,optical line terminal(OLT)can obtain the channel characteristics fingerprint of each legal ONU.However,the length of the local fiber and channel characteristics fingerprint applied by each legal ONU is secure to illegal ONU.At the received end of OLT,the identity of each ONU is authenticated by recognizing these channel characteristics fingerprints with trained NNs.Simulation results show that the system can effectively recognize the identity of each legal ONU.Moreover,when the length difference of the local fibers applied by the legal and illegal ONUs is greater than 1.5 km,the identity of each illegal ONU can also be recognized effectively.