Research On Physical Layer Encryption Scheme Based On Data Perturbation Technology In CO-OFDM

With the new concepts of 5G,Internet of things and artificial intelligence,Internet business has expanded rapidly,and the scale of data volume also increases explosively.This puts forward new requirements for communication technology.We need better communication technologies such as speed and bandwidth to support the transmission of network data and meet the needs of Internet services.The CO-OFDM technology combines the advantages of OFDM and coherent optical technology.It has the characteristics of high frequency utilization,can slow down the dispersion and polarization mode dispersion in the system,and become the main technology of optical fiber transmission system in the future.At the same time,with the surge of data volume,data security problems also follow.If personal privacy data is leaked on a large scale,it will have a huge impact on society.At present,there are many discussions about the security of the network,and various security enhancement methods have been put forward by the academia.However,considering the cost,complexity and security,security enhancement in physical layer is the most potential way.Therefore,this paper mainly studies the physical layer encryption technology of CO-OFDM system.In the physical layer,there are many ways to encrypt the communication system.In the CO-OFDM system,from the point of view of flexible design and no additional hardware cost,this paper chooses to implement data encryption by disturbing the signal in the electrical domain,which also combines the characteristics of OFDM signal and is easy to carry out digital signal processing.After investigating the algorithms in other encryption fields,this paper encrypts the data of CO-OFDM system based on data disturbance technology,so as to improve its security.The core of encryption is data disturbance.According to the location of data disturbance,two different encryption schemes are designed.Scheme 1 is a physical layer encryption scheme based on 2D-SCL mapping and Brownian motion,which uses 2D-SCL mapping and Brownian motion mathematical model to encrypt the frequency domain data of CO-OFDM system.Scheme 2 is a physical layer encryption scheme based on hyperchaotic mapping and DNA dynamic coding,which uses 4D Chen hyperchaotic mapping and DNA coding technology to encrypt the bit data of CO-OFDM system.The simulation system and experiments verify the feasibility of the two schemes,and ensure that the key space of the two schemes is above 1090 without affecting the communication performance,which can ensure the security of information transmission.The purpose of encrypting data by means of data disturbance is to introduce some strong random sequences into the original signal sequence,thus disturbing the correlation of the original information sequence,achieving the purpose of data disturbance and encrypting the original information.Because of the strong randomness and high unpredictability,the sequence with strong randomness will make it more difficult for illegal eavesdroppers to steal information directly.