Image Double Encryption Method Based on Chaotic Map and DWT

Image encryption becomes more and more important with the development of the network technology and the multimedia technology. A novel and secure image encryption method based on Chaos map and DWT is described at length in the paper. Firstly, we introduce two coupling chaotic maps to scramble an original image, and receive the scrambled image. Secondly, we transform the scrambled image by DWT. At the same time, we introduce a chaotic map again, and then we encrypt the wavelet coefficients of the scrambled image in DWT domain. In the whole process we use three chaotic maps, five keys and encrypt the image twice. Finally, we do many experiments and the experimental results prove our method to be secure.