The Application Researches Of Multimedia Information Security Algorithms Based On Chaotic Theory

With the multimedia technology and computer network technology rapid development,using open internet network to transmit data,such as,video,audio,images,and other multimedia information has become an important aspect of modern communication technology,but following, copyright disputes, tampering with data and secrets leak often arise.How to realize communication confidentiality, safety, high efficiency, is the precondition to use these convenient businesses, it's a study hotspot in information security areas.Encryption technology and digital watermarking technique is the effective protection means on multimedia information security.Chaos sequence has good initial value sensitivity and randomicity, ergodicity and huge key space ,it provides a new method for the information security .This paper mainly based on discrete chaotic theory , analysed thoroughly images, video media information security ,designed out some specific algorithm, which reflected the chaos effects in information security. The main contents include:(1) In chaotic theory, from the chaos mapping basic characteristics, researched the problems which were in discrete chaotic system application..Summarized and learned from existent improved measures, designed a kind of mixed chaotic key sequence algorithm,which can effectively improve the dynamic degradation characteristics.By experiment which encrypted compressed video data, the effect was better.(2) Analyzed the existing image encryption technology in airspace, from theory analysis and simulation proved airspace image encryption technology exists group relationship,given an encryption algorithm for a large size image, it limited little in image size, encryption speed was quick and only one round can achieve very good encryption results;Using S-box theory, proposed a obtaining S-boxes algorithm of chaotic iterative grid mapping based on the coupling model, and extended to produce S -boxes group, used to encrypt video data , it was speedy, high safety.(3) Using chaotic dynamics system, put forward two different function watermarking algorithm, one kind was half fragile watermarking algorithm based on image content authentication, the watermarking signal was embedded in DCT domain, it realized blind detection, and shown a good performance in resisting on LSB malicious deletion, JPEG compression, the algorithm can be applied to integrity authentication and tamperred positioning about image and video;Another was SVD-DWT mixed digital watermarking algorithm based on chaos, the watermark is embedded respectively in the different frequency bands of different layers,it better solved the contradiction between transparency and robustness, and can be used for authentication.Paper finally summarized the author's achievement, analyzed problems about the haotic theory and application researches , and put forward the future diligent direction.