An Image Encryption Algorithm Based on Scrambling and Chaos
Changci Wen · Journal of Information and Computational Science · 2013
With the rapid development of multimedia technology, secure algorithm of image communication becomes more and more important. Based on scrambling transformation and compound chaos, an encryption algorithm in spatial domain is proposed. Firstly, it scrambles pixel positions and confuses pixel values according to corresponding coordination under the control of chaos. Secondly, it takes nonlinear substitution and difiusion for all lines in the image. It iterates the upper two steps for at least 3 times to get the cipher-text. In the process of scrambling and substitution, pixel values are introduced to perturb compound chaos for adaptive encryption, and the scrambling function is compatible with images at any ratio of length to width without any preprocessing. Theoretical analysis shows that the algorithm has huge key space, and the mapping relation between the plaintext and the cipher-text is complex to e‐ciently defend attacks. Experiments show that the algorithm achieves strong sensitivity, conforms to confusion and difiusion principles in cryptography, and gets high security.