Research On Channel Encryption Technology Based On Nonlinear Transformation Pair

Communication and information transmission can be seen everywhere in people's lives,their security is of vital importance.In order to further improve the security of data transmission in communication,in addition to the source encryption and coding,it is also strongly necessary to implement channel encryption to increase data security.In this paper,channel encryption is deeply studied,and two channel encryption methods that based on amplitude distortion and phase-distortion are described and analyzed.Meanwhile,a communication system is designed to verify the feasibility,reliability and confidentiality of the two encryption methods.Firstly,this dissertation describes the basic principle of two channel encryption methods based on amplitude distortion and phase distortion.The design method of nonlinear transform pair based on amplitude distortion and nonlinear phase all-pass filter pair are studied.Based on the above two channel encryption methods,the simulation experiments for encryption effect are executed.Secondly,the overall implementation scheme of the verification system for the two channel encryption algorithms is designed,based on the high performance digital signal processing board,which is divided into three modules: the transmitting end,the receiving end lower machine,and the receiving end upper computer.At the same time,the key technologies in the system implementation are briefly analyzed.Then,the verification system is implemented in detail.Among them,the frame structure of data transmission in the verification system is designed,which effectively improves the information recovery efficiency of the receiving end;utilizing C++ to implement FFT,convolution,FIR filter design,root raised cosine filter design and other digital signal processing operations in the software of receiving end upper computer,which avoids installing various third-party digital signal processing libraries and greatly streamlining software structure.In addition,the encryption methods are tested and the symbol error rate is analyzed.Experimental results show that the two encryption methods can well realize the encryption and decryption process of signals in this verification system,which is well worth referenced for the research of data security transmission..Finally,the paper implements high-speed data transmission between receiving end lower machine and receiving end upper computer that including data transmission between FPGA and DSP,data transmission between DSP and host PC.High-speed,stable and reliable data transmission guarantees the running accurately of the whole communication system.