Quantum Image Encryption Scheme Based On Improved Arnold Transform

As the important carrier of information, images are used more and more widely in today's society life. In recent years, there are many cases that image information leakage bring loss to personal privacy, companies and even the country. With more and more high requirements of image security, image encryption technology becomes a challenging field.Classic Arnold transform can be implemented to permute pixel position under the condition of unchanging pixel values of image. the experimental results show that the number of iterations is greater than 5 to get good scrambling effect. But the algorithm has a fatal flaw for encryption system: classic Arnold transform is cyclical. This paper proposes an image encryption algorithm based on general Arnold transform with keys and quantum chaotic map. The algorithm is designed to overcome the periodicity, and make the correlation between two adjacent pixel, the number of pixels change rate(NPCR), the unified average changing intensity (UACI), key space, the information entropy better. The experimental results show that the algorithm is more secure than classical Arnold transform.In order to obtain perfect key sensitivity, the key generator based on the two-dimensional Logistic map is designed to get the initial parameters by means of address mapping; In the encryption stage,general Arnold transform is added a pair of keys. In the process of replacement the pixel position is changed, at the same time each pixel value is modified by the pseudo random sequence generated by quantum chaos system, which realizes gray-level encryption. In order to get the high randomness and the high complexity, the two-dimensional logistic map and quantum chaotic map are coupled with nearest-neighboring coupled-map lattices (NCML).