Study Of Chaos Based Digital Information Encryption Algorithm

Multimedia information has become a main way for information communication along with the rapid development and the wide use of computer, network and multimedia technology. However, the transparence of digital multimedia information over network also facilitates unauthorized copying and intentional tampering. Therefore, multimedia information security problems became a pop international research question.This paper studies based on DSP chaotic signal generation, image encryption and video encryption,The main contributions of this dissertation are:1) Studying the basic characteristics of chaos and several typical of chaotic system dynamics behavior, the traditional encryption methods, and points out that the traditional encryption methods existing problem.2) Firstly introduces chaos theory and the basic characteristics of chaos. Owing to the broad application prospect in information security field, the study of digital chaotic circuits becomes a research focus in field of chaotic engineering application. This paper presents a method of 3-D digital chaotic circuit implementation based on DSPTMS320F2812. Through modifying model, the different 3-D chaotic systems are implemented easily by using this method. The experimental results are in good agreement with computer simulation, which demonstrates the effectiveness and flexibility of proposed method.3) This paper presents a new image encryption algorithm, in this algorithm, shuffling matrix and diffusing matrix are generated based on Chen's hyper-chaotic system. Firstly, the Chen's hyper-chaotic system is used to shuffle the position of the image pixels, then use Chen's hyper-chaotic system to confuse the relationship between the original image and the cipher image. The experimental results demonstrate that the encryption algorithm of image has the advantages of large key space and high security. Owing to more complex dynamical behaviors, the proposed encryption algorithm is more secure than some chaos based encryption algorithm.4) Video information to address security issues, this paper presents a hyperchaotic system based on video encryption algorithm and block cipher stream encryption combined stream cipher used to generate random sequence, block encryption to scramble data. Stream encrypted by the two-dimensional discrete chaotic system to produce ultra, block encryption generated by the super-chaotic system. And security analysis algorithm to verify security of the algorithm.