Research And Implementation Of Video Chaotic Encryption Based On H.264

With the improvement of science and technology and the development of multimedia technology, the information technology has been permeated into all walks of life. The security of information has aroused more and more attention of people, so that how to strengthen the security of information has become a problem to be solved. One side, the H.264codec technology has been a research focus of video codec technology for its high compression ratio and good network adaptability. On the other side, the characteristics of chaotic system, including high sensitivity to initial conditions and system parameter, the topological transitivity, wide spectrum, aperiodic and motion orbit of ergodicity, are consistent with the diffusion and mixing characteristics of modern cryptography, which shows a natural connection between chaos and cryptography. And applying the chaos theory into information security has broad prospects for development. At present, the algorithms for information encryption almost are presented on the PC platform, but not for the embedded device, which means the embedded device can’t enciphered information with the algorithms because of the limits of the devices. However, chaotic encryption work it out. Applying the chaotic encryption algorithm into embedded system equipment has vast potential for future development. The main contents researched in this paper include:(1) The system studied the chaos theory, and proposed a new chaotic video encryption method, which scrambles the position of U in YUV format video frames and V frame by cat map, then encrypted the Y frame in the video by the chaos sequence generated with the improved Wang-Chen algorithm. And analyze it on the security of the algorithm and encryption speed, which ensure the structure of the video is not damaged and encrypted with a well-pleasing speed. The experiment results show that the encryption algorithm is sensitive to the key, and has large key space, have stronger resistance to a variety of attack. The encryption algorithm has high encryption security, and synthesizes the advantage of stream cipher and block cipher, not changing the code structure of video streaming, and encryption speed and good effect. Although the cat map will decrease correlations between video frame data, but results of experiments show that it barely affect the compression coding process of video.(2) Set up the hardware and software environment for the development of embedded Linux systems. Made some simple analyzing about the hardware referred to the embedded platform, and transplanted the embedded Linux operating system to target platform. Including the bootloader, the Linux kernel and root file system and related hardware drivers. Completed the debugging of the ARM platform based on embedded Linux.(3) Summarized the basic principle and overall structure of the H.264codec briefly and illuminated the key technology in details. The transplantation of H.264codec on ARM platform is mainly introduced.(4) Design a chaos encryption system for video based on H.264. Because encrypted the video before coding, so the system can be applied to all the businesses in H.264standard such as video conference、digital broadcast television、video monitoring、 streaming media、etc, which has important practical value.