Digital Image Information Hiding

With the rapid development of information age, there are various multimedia information in the Internet. More and more people choose internet to transfer messages. Thereby, requestion of fairly high security in order to sending and putting out safely information for both individual person and government is important.Then the information security techniques are greatly demanded. The information security is involved in many fields.In contrast with encryption, the existence of communication process and both communication sides is bided in the information hiding technique. Even if the cover is intercepted by illegal users, the secret message can not be revealed because they do not know whether the secret message exists or not. The encryption method make the secret message into confused code, and only some one who hold the right key can access the secret information. In encryption,when the code is captured by the sniffers, they may determine that they have got another form of the secret and the next step is to decrypt the secret from the disordered code。In this paper, some algorithms of data hiding based on the digital image and text are developed from the practical points. The main content of the dissertation are summarized as follows.1. According the analyzing to various attack of information hiding systerm , the provable security theory of information hiding systerm, generalized information hiding and the protocol of information hiding, this paper study the security of information hiding systerm.This paper proposed a disguise hiding incertitude security strategy.2. This paper use the distance of characters to code the text. First, use a rule to organize some words to a group, then classify the groups. At last, according the segment classification hide the watermark information. The experiment results conclude that the method is effective.3. Depending the analyzing of SVD decompose to the photo matric,this paper present an asymmetric watermarking method for copyright protection that uses different matrix operations to embed and extract the watermark.We have two watermarks,one is the traditional watermark which based on original image and another is a gray image which is a symbol image. It allows for the public release of all information, except the secret key. We investigate the conditions for a high detection probability, The robustness of our method is demonstrated by the simulation of various attacks and the result is satisfied.