Image Encryption Algorithm Based on Chaos and Wavelet Transform

Because of the features of initial value sensitivity,parameter sensitivity and random sensitivity,a novel image position scrambling method,which is called chaos transform,is firstly presented.And a practical image encryption algorithm based on wavelet transform and chaos transform is put forward.Four steps are included in our algorithm.Firstly,to preprocess the original image by chaotic system.Secondly,to decompose the preprocessing image by wavelet transform and to get four sub-images.Thirdly,to scramble the four sub-images by chaos transform on same keys.Finally,the encrypted image is obtained by inverse wavelet transform of the scrambling coefficients.Experiment result shows that the encrypted image and the original image have good identity.And our algorithm has good safety.