A novel color image encryption algorithm based on spatial permutation and quantum chaotic map

In recent years, several algorithms of secure image encryption were studied and developed through chaotic processes. Most of the previous algorithms encrypt color components independently. In this paper, a novel image encryption algorithm based on quantum chaotic map and diffusion-permutation architecture is proposed. First, the new algorithm employs the quantum logistic map to diffuse the relationship of pixels in color components. Next, the keystreams generated by the two-dimensional logistic map are exploited to not only modify the value of diffused pixels, but also spatially permute the pixels of color components at the same time and make the three components affect one another. Finally, the random circular shift operation is applied to the result of the modified and permuted pixels to rearrange bits of each encrypted pixel. In order to achieve the high complexity and the high randomness between these generated keystreams, the two-dimensional logistic map and the quantum chaotic map are independently coupled with nearest-neighboring coupled-map lattices. The results of several experimental analyses about randomness, sensitivity and correlation of the cipher-images show that the proposed algorithm has high security level, high sensitivity and high speed which can be adopted for network security and secure communications.