Design And Implementation Of Chaotic Voice Secure Communication System Based On ARM11

Chaos is an irregular random movement that occurs in a certain system. As people pay more attention to information safety, secure communications through chaos are concerned more and more. However, present studies on secure communications through chaos are mostly based on analogue circuit, and even when the digital circuits are used, it is mainly on digital platforms without a good portability, such as DSP, FPGA etc., thus it is hard for producing. A safe, compatible and easily-used secure communications method becomes the focus of study, together with the development of Internet of Things and intelligent wireless mobile communication system. In this thesis, based on chaotic theory, numerical simulation and experiment, a digital chaos synchronic system is implemented which is embedded in ARM 11 on Linux system, and it can be used in the sound secure communication system. The work of this thesis is as follows:Firstly, the traditional Lorenz chaotic system is discretized, and C language is used to realize the Lorenz chaotic system in Linux system based on PC. Then it gets the Lorenz chaotic generator that runs on ARM and embedded Linux by the PC-ARM cross compiling circumstance.Secondly, the synchronization method based on state feedback for Lorenz chaotic system is proposed, single-state feedback synchronization controller is designed, which is proved by Lyapunov method. The controller gain range is gotten, and numerical simulation results show that the proposed controller can achieve complete synchronization. Furthermore, Lorenz chaotic synchronization program for ARM is given; some chaotic synchronization experiments are done. The experimental results show that the synchronization is very ideal and suitable for the development of secure communication systems.Thirdly, internet communication module, audio processing, audio encrypt & decrypt module are designed based on the Lorenz chaotic generator and synchronization program. The problems, which the numeration system are not uniform and the values do not meet the requirements the process of encryption and decryption, are solved. Chaotic secure communication system is developed, and it is successfully achieved by WIFI module based on TCP/IP network protocol.Finally, a summary has been done for all discussions above. The further and more deeply researching works are presented.