Abstract: Encryption of images is different from that of texts due to some intrinsic features of images such as bulk data capacity, high correlation among pixels and high redundancy, which are generally difficult to handle by traditional methods. Due to the exceptionally desirable properties of mixing and sensitivity to initial conditions and parameters of chaotic maps, chaos based encryption has suggested a new and efficient way to deal with the intractable problem of fast and highly secure image encryption. In this study, an image encryption scheme is presented, in which shuffling the positions and changing the grey values of image pixels are combined simultaneously to ensure a high level of security. Firstly, the Arnold cat map is used to shuffle the positions of the image pixels in the spatial-domain. Then another chaotic map is used to confuse the relationship between the cipher image and the plain image. In the proposed image encryption scheme, an external secret key of 128-bit is employed. Further, to make the cipher more robust against any attack, the secret key is modified after encrypting of each pixel of the plain image. Thereby, significantly increasing the resistance to statistical and differential attacks. Visually and computationally, experimental results demonstrate the high security and significantly superior encryption quality of the proposed scheme.
I.A. Ismail , Mohammed Amin and Hossam Diab , 2007. An Efficient Image Encryption Scheme Based Chaotic Logistic Maps. International Journal of Soft Computing, 2: 285-291.