Image Hiding Technology Based On The3D-CA And FRWT

The event of the "Prism door" has happened in public，countries realizing that howserious is the information security is threatened. The security of the militarycommunication becomes a hot topic nowadays, how to ensure the safety transmission ofmilitary image is the part. Digital image plays an important role in the informationtransmission, it has the characteristics of the image, easy to understand, large amount ofinformation. However, for the important information as the military equipment picture, theimportant target region images and the satellite images and so on, it is extremely unsafe totransport directly in public, the consequences are unimaginable——minor consequences asdisclosure leading to battle defeat, serious consequences as the national humiliation. Thetechnology of military image hidden communication arises at the historic moment. It did inthe case of without the authorization of the sender and the recipient, a third party can’tbrowse and steal information. It first to encrypt the secret image preprocessing, and then tohide, achieves the confidentiality and invisibility at the same time.Modern encryption technology mainly includes DES, RSA and chaos encryptionmethods, and so on. But the study found that those algorithms have disadvantages asnot-high complexity, small amount of keys, encryption or decryption complex and evendegradation easily as a periodic sequence. The information hiding algorithm mainlyfocused on the airspace and transform domain at present. Airspace algorithm is based onthe operations of the pixel values of the image data to achieve information hiding, such asLSB algorithm, this method has large hiding capacity, but shortcomings such as lowcomplexity and poor ability to resist attacks. Transform domain algorithm is to encode thefrequency of the image global data to achieve information hiding, such as discrete cosinetransform, discrete wavelet transform, fractional Fourier transform, fractional wavelettransform method, transform domain algorithm has strong robustness, and can maintainhigher imperceptible.This paper uses encryption pretreatment by the method of cellular automata encryption, building a three-dimensional cellular automaton （3D-CA），using the role of scattering ineach cell in the grid (Cell) of3D grid to synchronize updates, in order to make a lot ofcellular automata through simple interactions and then constitute a complex dynamicevolution system, which posses a large number of discrete degree of freedom, structure issimple but behavior is abnormal complex, has the very good avalanche effect, so it has highersecurity performance. The paper uses a new type of fractional order FRWT in hidden method,takes advantage of wavelet decomposition’s good invisibility and robustness of fractionalorder FRWT, gets the secret image after fractional transformation hidden into low frequencycoefficient of the carrier images, balances the contradiction between the robustness andinvisibility in these two kinds of algorithm. Experiments show that the algorithm not only hasa strong ability to resist geometric attacks, but also has high good resistance to aggressivesuch as gauss, shear, and filtering, what’s more, has good invisibility, large capacity ofhiding.