Research On Image Encryption Algorithm Based On Chaos Theory

Image encryption technology is based on the traditional encryption theory. It is akind of encryption method to ensure that the data of image with the secrecy in thetransmission process. Its purpose is to put the image which needs encryption convertedinto an image beyond all recognition according to certain some algorithm, and makethe stealer can’t get the image true information. Image encryption technology plays animportant role in multimedia communication technology, and gets many scholars’favor. More and more encryption methods have been worked out and the results werevery good in the practical application.At present chaotic system combined with encryption technology is a morepopular subject, although there are a lot of encryption algorithms, but these encryptionalgorithms is not mature, and still need further research. This article combines thepixel position scrambling transformation with pixels alternative transform, and designsa kind of image encryption algorithm which is based on chaos digital. Wavelet theoryis combined in the transformation design, and the affine transformation in the integerdomain is used. It studies a method of scrambling frequency coefficient matrix. The2-d logistic chaos mapping is used in the design of the pixel grayscale value replacement,and puts forward two kind of replace thoughts. In the algorithm,1-d chaos mappingand2-d logistic chaos mapping are combined and produce the many chaotic sequenceswhich control pixel scrambling replacement and grey value replacement. Many chaoticsequences produce key space more than a single chaotic sequence generated key space.So encryption strength of the algorithm is very high. Through the crack experimentand performance analysis, the results show that security of the algorithm is very good,and it can resist certain malicious attacks. Under the condition of the ciphertext imagedefect, this method can also reduce the original information, so effect of the encryptionis very good.