Based On Chaos Theory Of Wavelet Domain Image Encryption

Nowadays,with the rapid development of information technology,imageinformation, as a branch of information technology areas, is widely used and spread atvarious level. However, people increasingly put emphasis on the importance ofinformation security.So the scrambling image encryption algorithm can not meet therequirements of high standards of the current information security any more becauseof its existing shortcomings.In order to promote the security of image information,based on the study of wavelet transformation and chaos theory, this paper proposes achaos theory of wavelet analysis of image encryption algorithm.The paper design is a kind of wavelet domain image encryption algorithm basedon the chaotic theory, including image algorithm design framework, image algorithm,the experiment and analysis, and also study the analysis of the image encryptionalgorithm and constructions. Algorithm firstly transforms the image with walve, afterscrambling to get subband coefficients matrix for wavelet reconstruction to achieveimage encryption for the first time, and then generates chaotic sequence with thechaos system to form key, keys and initial encryption image processed to getencryption image, the process of encryption is in reverse.finally a clear image can bereceived. Those parts-key space, key sensitivity, statistical histogram of image andcorrelation of adjacent pixels are able to be analysis via the tool of MATLAB,thenobserved the actual effect of the algorithm. The experimental results show that theencrypted image has good safety and anti-interference, easy to implement, andapplication.In this paper, the main work includes the following:Firstly, the domestic and foreign development status of image encryptionmethods are studied. Aiming at the shortage of key security of image encryptionalgorithm, After analyzing association, common points and differences of chaotictheory and cryptography, with key sensitivity characteristics of good use of chaostheory, this paper proposes that the encryption system uses chaos encryption form todesign. Secondly, an image encryption algorithm using chaos sequence is proposedafter analyzing the wavelet, which has the characteristic of transforming flexibly intime domain and frequency domain. The algorithm has good anti-interference ability to attack. Thirdly, the image encryption and decryption system architecture wasconstructed. the encryption system contains four modules, each module in related witheach other completes the image encryption and decryption. Image encryption thoughtis the image, based on the chaos theory and wavelet transformation, generates lowfrequency coefficients, then forms first encrypted image,using wavelet reconstructionafter scrambling transformation. Lastly the encryption algorithm of pixel valuescrambling is used again. Finally, through MATLAB simulation experiment andtheoretical analysis, the algorithm of image encryption algorithm safety, the keyspace, key sensitivity, statistical analysis, malicious attack and so on, proves thesecurity method has very good encryption effect and high safety, through thealgorithm analysis experiments to prove, in various interference to attack thisalgorithm can effectively resist, meet the requirements of image encryption. Finallysummarizes the full text, and pointed out in this paper, existing deficiency and thedirection of further research in the future.