Design And Implementation Of Chaotic Image Secure Communication System Based On ARM

Chaos is a motion that occurs in a nonlinear system,which appears to be random but not completely random.It is widely used in signal processing,secure communication and image processing because of its sensitivity to initial values,seemingly random and unpredictable.As the image with high redundancy,large amount of data and strong correlation between the intrinsic characteristics of the pixel,the conventional encryption algorithm can not meet the communication requirements.At present,some scholars have used the hardware platform to realize the chaotic secure communication.The anti-jamming ability of the simulated chaotic secure communication system is poor and the parameter matching is not accurate.The digital technology overcomes these problems,but the digital chaotic secure communication is still in the theoretical research stage.At the same time,embedded ARM platform has strong data processing and data transmission functions,so the design and implementation of chaotic secure communication system based on ARM is of great practical significance.In this thesis,based on the reality,the main research contents of this thesis are as follows:Based on the ARM platform,the main contents are as follows:Firstly,a cross-development environment consisting of a general-purpose computer and a development board is built.And use this environment to cross compile the Linux operating system.In order to make the chaotic image secure communication system have excellent man-machine interface,the function library Qt/Embedded and Qt Creator are transplanted,and the graphical interface development environment is established.Secondly,as the chaotic cryptosystem is highly dependent on the key,there is a hidden danger in the key transmission process.In this thesis,chaotic synchronization method is introduced,and encryption and decryption algorithms are proposed for pictures and video respectively.The structure of the drive-response system is constructed based on the super-Chen system.The state feedback method is used to realize the synchronization.The data is encrypted and decrypted using a stream cipher algorithm based on scrambling and spreading.An encryption algorithm based on chaos synchronization and scrambling,diffusion principle and initial increment is proposed for image files.Furthermore,for the real-time video files,considering the fluency of video decryption,this thesis proposes the chaos synchronization and scrambling principle.Thirdly,the scheme of the system is designed.The security subsystem of chaotic picture and the secure communication subsystem of chaotic video are realized by selecting ARM as the platform.The main functions of the system include:data transmission in LAN,image acquisition and real-time display,encryption and decryption of image and human-computer interaction function.At the same time,the functions of chaotic image secret communication subsystem and chaotic video security communication subsystem are analyzed respectively.And the security performance of the system is analyzed from three aspects:key generation process,histogram of image and pixel correlation.Finally,after summarizing the research work of this thesis,I make the main conclusions of this thesis and point out the direction to be further studied in the area of the chaotic image secure communication.