Research On Information Hiding Algorithm Of Digital Image

As important research filed of information security technology, information hiding technology has important research significance for safe transmission of secret information. By using human sensory organs insensitivity for redundant information, information hiding technology hides the secret information into the redundant information of public information and then transmitted the carrier image. Carrier information after embedding secret information shows features of public information and not only it can transmit without being aware of circumstances but also improve security of information security system. Compared with information encryption technology, information hiding technology not only hides existence of secret information, but also hides communication process of secret information and then communication of the secret information without being aware of circumstances. The main work and research result can summarize following the three parts:Firstly, image encryption algorithm using composite chaotic was proposed. The algorithm generates weights according to chaotic Logistic mapping and the two key images combined into a new key image according to weights with the purpose of increasing the key space. According to matlab simulation experiment and the related theory of image encryption algorithms, the image encryption algorithm has the strong ability to resist attacks that statistical analysis attack, differential analysis attack, correlation attack and information entropy analysis attack and has a strong key sensitivity.Secondly, lossless data hiding algorithm using ranks and columns transformation was proposed. The original intention is that in order to use correlation of diagonal pixels, the image needs to execute ranks and columns transformation with the purpose of constructing pixels difference of diagonal direction. Then the matrix needs to shift pixel difference histogram and embed hiding information to the specified difference of pixel difference histogram. After extracting hiding information, the algorithm can restore the original image losslessly. The experiment results show that PSNR/bits of the algorithm is lowest or close to lowest than algorithms of references from [30] to [40].At last, information hiding algorithm using statistical analysis was proposed. The main idea of the algorithm is that carrier image needs to slice and extract the second bitmap and the third bitmap of carrier image. The same bit information was embedded in the corresponding position of the second bitmap and the third bitmap. During extracting hiding information, the bit information needs to determine according to the law of statistical analysis. The simulation experiment results indicate that on the premise that secret image has a better visualization quality, the algorithm has a better resist ability of pepper and salt noise attack, Gaussian low pass filtering attack, shear attack and random doodling attack.