Image Encryption Based On Reversible Cellular Automata

Along with the development of network and multimedia technology, the security of information transmission and preservation is getting more and more important to the society. It is one of important means to exchange information between the people through browsing the digital images. The digital images play important role in the modern information society, they bring more convenient to the people. At the same time, some image data as the reason of individual privacy, copyright and so on, need to be encrypted. Image data protection has been noticed in the society, that causes the image encryption technology also becomes very important.The cellular automaton may apply to the digital image encryption technology by its divergence in space, time and state. One kind of new image encryption algorithm based on the one dimensional reversible cellular automaton is proposed. The new encryption algorithm converts the known gray image to two value image, then arranges these data in 0 and 1 sequences. Together with the same dimension 0 and 1 pseudo-random sequences as the initial data, the reversible cellular automaton rule is used to realize the image encryption. To general request of the digital image encryption, one evolved rule of the reversible cellular automaton may be used. The security of one rule encryption is low, but the real time performance is better. To the high request of digital image encryption, several evolved rules of the reversible cellular automaton may be used. The security of several rules encryption is high, but the real time performance is not good. Considering evolved rules and evolved steps according to the given digital image, the security as well as the real time performance of the encryption and decryption algorithm may be optimized as far as possible.Indicated by the results of the gray image encryption simulation, the image encryption algorithm based on the reversible cellular automaton satisfies with the properties of confusion and diffusion. The encryption effect is better. Meanwhile, through the privacy key analysis, the histogram analysis, the information entropy, the average value of gray change and the relevant analysis, the security of this algorithm is very high.