Image scrambling encryption algorithm of pixel bit based on chaos map

This paper presents an image scrambling encryption algorithm of pixel bit based on chaos map. The algorithm takes advantage of the best features of chaos maps, such as their pseudorandom property, system parameters, sensitive dependence on initial conditions and un-periodicity, combined with the pixel value bits. The new algorithm uses a single chaos map only once to implement the gray scrambling encryption of an image, in which the pixel values ranging from 0 to 255 are distributed evenly, the positions of all pixels are also permutated. In this way, the proposed method transforms drastically the statistical characteristic of original image information, so, it increases the difficulty of an unauthorized individual to break the encryption. Finally, the numerical experimental results show that the image encryption algorithm suggested has perfect hiding ability including large key space, sensitive key to initial conditions, high gray scrambling degree, and is suitable for practical use to protect the security of digital image information over the Internet.