A Multiple Tent Maps Based Image Encryption Scheme with Plain-image Dependent Permutation and Diffusion

A novel multiple tent maps based image encryption scheme with plain-image content dependent permutation-diffusion mechanism is proposed. The permutation is realized by swapping the gray values at different part of the considered image; it is performed with the help of pseudo-random sequence yielded by tent map, which is different from conventional permutation within the whole plain-image, and therefore improves the permutation efficiency. The diffusion is performed over the permuted image by bitxoring operations with pseudo-random gray value sequences generated by two other tent maps. The key streams for the two processes are both related to the image contents, and consequently the proposed image encryption scheme is strongly sensitive to cipher keys as well as plain-images. One round of permutation and one round of diffusion achieve perfect security effect. The security and performance of the proposed scheme have been analyzed thoroughly in details.