The Application Of Information Hiding And Its Security Analysis

The rapid development of the Internet has brought not only a lot of convenience but also some security problems. From the view of the whole country or the individual, information security has become an urgent problem to be solved. As an effective technology, information hiding plays an important role in protecting information. However, there exist the following problems about information hiding at present: 1) The purpose and the means of hiding analysis become diversified; 2) The ability of the attackers to the analysis of the information hiding has been improved. Therefore, the research of the secure hiding model and the accurate assessment of the security of the existing hiding model are of great importance.This paper try to study the security of the general model of information hiding by applying the theory of information and hypothesis testing. In addition, a prefect information hiding model is put forwarded based on the definitions and principles of information hiding. The perfection of the model is proved by mathematical deduction, and is also verified by the theory of information and hypothesis testing.One of the important application of information hiding is covert communication. Its purpose is to conceal the contents and the existence of the secret message. In this paper a perfect covert communication scheme is proposed. There are three aspects have been discussed. 1) The carriers must have rich information and colors because of the properties of covet communication. So, the image entropy and the histogram are used to select those carriers. 2) The extraction algorithm and the detection algorithm are used to describe the communication process. 3) The difference function defined by conditional entropy and mutual information theory is used to analysis the security. The security level is defined as the value of the difference function. It shows that the randomness of the model and the redundancy of the carriers have greatly improved in the security.Another pop application within information hiding is digital watermarking. Its purpose is the guarantee of the long existence of the watermark. This paper also proposes a perfect digital watermarking scheme based on the perfect information hiding model. The watermark is embedded in the edge and texture region of the carriers in order to improve the performance of the system by using the fuzzy entropy algorithm. Then, we use the perfect hiding model to choose the hiding position of the very features with the purpose of the increase of the randomness and the uncertainty. Finally, the watermark is embedded in the DCT coefficients. It shows that the scheme proposed is of high security, good imperceptibility and strong robustness.