Research On Unconditional Security Agreement Based Image Hiding And Image Authentication Technology

With the development of informatization, the digitization of information has become the typical signs of the new economic, and the information security has become the focus of international society. At the same time, the increasing requirements of the digital media security have greatly promoted the development of the information hiding and digital watermarking technology, and it has became a hot research topic of the information security field. In this paper, we study the existing results of the information hiding and digital watermarking, the image hiding scheme which is based on the visual cryptography is improved, and then an image authentication and copyright protection scheme is proposed based on the unconditional security agreement. Main works are as follows:The (r, n) threshold secret sharing and digital hiding technology are studied. Based on the idea of visual cryptograph proposed by Shamir, we combined the image secret sharing and digital watermarking technology to achieve an image hiding scheme that is based on (r, n) threshold secret sharing. On Matlab7.6 platform, we simulated and demonstrated a series of attack experiments. The experimental results show that our scheme is robustness against low-density noise and small area of the cutting, and able to extract the information of valuable secret image.The copyright protection scheme for color image using secret sharing and wavelet transform proposed by Hsieh in 2005 is studied. We found that this scheme is complicated in algorithm, and experimental analysis have some shortcoming, then we improved the scheme which proposed by Hsieh from reducing the complexity of the algorithm. The improved scheme uses the gray and color images as research object, it does not need to design the watermarking embedding algorithm, using the unconditional security protocol to achieve the image integrity authentication and copyright protection. In the phase of the watermarking generating, we use discrete wavelet transform to decompose the images, then we use low-frequency wavelet sub-band of the image to generate the watermark shadows which can be divided storage. In the authentication phase, the same technology is used to the suspect images, then using the image authentication algorithm to achieve integrity certification. Simulation experiments is carried out on Matlab7.6 platform, the experimental results show that the proposed scheme can resist several attacks such as JPEG compression, blurring, sharpening, noise addition, rotscal, mediancut, which are generated by stirmark.