The Research On Video Secure Communication Based On Spatiotemporal Chaos

In recent several decades, the researches on chaos theory in non-linear dynamics have achieved a great development. Nowadays, chaos secure communication has been one of the focuses, especially since the breakthrough in chaos synchronization made by Pecora and Carroll in 1990. At present, the security in Network is an increasingly serious problem. As to the security of modern Network, Secure communication on the multimedia is the issue to be resolved urgently. It is not only a new field in the application of chaos, but also a challenge in chaos secure communication. These problems, such as the efficiency of encoding and decoding, the security of communication systems, and the performance against noise, are waiting for us to analyze and study further.In this thesis, we gave attentions to the researches on video encryption and video communication based on spatiotemporal chaos. The major contributions and innovations include:Firstly, we designed an encryption algorithm for video based on the spatiotemporal chaotic systems. The creation is not only the application of spatiotemporal chaotic systems to the actual video encryption, but also the universality. It is means no format requirement of the compressed video files.Secondly, we have applied spatiotemporal chaotic theories to the practice of video stream's secure communication in Network. Both sides realized the on-line and real-time correspondence of encoding and decoding video data. What's more, the secret key streams are highly sensitive to any changes and have a large space. Thus, the secure communication system can work safely and has a good performance against the attacks.Thirdly, Instead of using one-dimensional coupled map lattices model, we have constructed a combinable model, which is consisted of an one-dimensional chain, a two-dimensional netting grid and another one-dimensional chain as the drive-response system. So both the system's complexity for secret key streams and the efficiency for encryption have been increased.The first practical application system introduced in this thesis is"encryption system based on spatiotemporal chaos", which accomplished the function to encrypt and decrypt video files in AVI famat. The spatiotemporal chaotic system peforms a function as secret key streams'generator which is the critical constitution related to security. So there is a test unit to analyze the characteristic quantity of spatiotemporal chaotic system, and to ensure stream's randomness further. The second instance is"video secure communication system between Server and Client". Considering the characteristic and real-time requirement of the video stream transmission, the system utilized an improved coupled map lattices model to realize encoding and decoding with parallel method. The experiment result is that, both the speed of video stream's encoding and the on-line synchronism show good performance.