Image Encryption Algorithm Based on 2-D Wavelet Transform and Chaos Sequences

摘要

Because of the features of chaos sequences, a novel image position scrambling method, which is called new chaos transform, is firstly presented. And a practical image encryption algorithm based on 2-D wavelet transform and chaos transform is put forward. Three steps are included in our algorithm. Firstly, to decompose the image by 2-D wavelet-transform and get four sub-images. Secondly, to scramble the low frequency sub-image and the high frequency sub-image 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 higher safe performance with satisfactory experiment results.