Research On Text Based Information Hiding Technique

With dramatic advance of Internet and wide application of the multimedia technology, information-hiding techniques have become a new hot topic in the domain of the information security. Today's information hiding techniques mainly use image, audio and video as cover objects. Techniques using text as cover object are relatively fewer because of its speciality.But as a matter of fact, a large number of text data are transferred or exchanged on Internet by people every day. Which makes it is a very import secret communication channel to use text as cover objects.Since this,the text hiding techniques are discussed in detail in this paper.In the thesis, firstly we introduce the basic concepts and theoretics of information hiding technologies and digital watermarking, such as charachteristics, classification and application and so on. Then we analyze the iformation hiding techniques based on text in detail and give a survey of today's popular algorithms of text document information hiding and their advantages and shortcomings.Text watermarking is a very important application area of text information hiding. After studying the deficiency of present text information hiding and text watermarking, a novel zero-watermarking algorithm based on English text content is proposed in this paper. In this algorithm the text characters are firstly determined by the punctuations, and then by XOR the encrypted characters and the encrypted watermarking information, the watermark is embedded into the text. The experimental results show that the algorithm has complete hiding effectiveness and strong robustness. Zero watermarking is proposed from images based information hiding technology. Before this, all watermarking algorithms, for embedding watermark information, authors modify more or less original image data through various methods to limit its robustness and security. Zero watermarking is a new digital watermarking technology without modifying the data of original cover.Finally, this paper analyzes the zero text watermarking technology and proposed a text based information hiding method. The method focuses on the hidden nature of the information. In the process of the embedding, not modify any original cover data, hidden information is embedded into the text according to the character' Unicode odd or even and with some special rules. The method has been finished by programming and had some robust testing. The experimental results prove that the method has a large capacity, good hiding effectiveness and strong robustness and so on. In my opinion, the method has two following innovations: (1) complete hiding effectiveness; (2) Resist text regeneration (such as print, scan, copy). However, the method can only be applied to information hiding, not be used for copyright protection, yet to be improved.