An image encryption method based on selective AES coding of wavelet transform and chaotic pixel shuffling

Image encryption is a mainstream aspect in multimedia applications and as such it is a highly active research domain. Based on the increasing need for reliable image encryption this paper presents a new method which combines the Haar wavelet transform with the Advanced Encryption Standard (AES) and pixel shuffling based on a chaotic logistic map. In the proposed method the Haar wavelet transform is calculated from the original image to obtain the different frequency domains of the image, namely, the approximation coefficient (LL) and detail confidents (LH, HL and HH). The approximation part (LL) is then encrypted by using the AES algorithm to create the image diffusion and the inverse of the Haar wavelet transform is applied. To further enhance the encryption strength a chaotic logistic map is used to shuffle the resulting image thereby making a malicious reconstruction attempt very challenging. The proposed method was evaluated in an extensive set of tests and compared to several representative methods from the literature. Test results show that it performed well across a variety of images and achieved a better level of image encryption and a lower level of image degradation.