Research And Implement Of Information Hiding System Based On Word Document

The information hiding technique can hide the content and existing of information and it is an important method to insure the computer network information security. It is becoming one of hot research topics in information security field. On the basis of studying, summarizing and analyzing the existing algorithms, this paper designs two novel methods based on word document, and implements two information hiding systems based on the methods respectively. The first one is word information hiding algorithm based on watermarking fragments regrouping strategy. In the algorithm a character's three color features (font color, underline color, and border color) are utilized to embed watermarking based on the fragments regrouping strategy. Experiment results show the method has the following advantages:stronger watermarking robustness, greater watermarking capacity, better watermarking imperceptibility and better expansibility compared with most of the existing information hiding algorithms. The algorithm is intended to protect the watermark information embedded in the document from being lost, mainly used on recovering the copyright of the publicly available document. The second one is word information hiding algorithm based on structured storage. It mainly applies to the word 2003 or earlier version. Taking into account the defect that the existing information hiding algorithms can not embed information in a blank document, the method can embed a large amount of data in word document's internal structure by employing structured storage principle of compound files and VSTO plug-in mechanism. Experiment results verify that the method is not relevant to document content, and has higher efficiency, easier implementation and less time consuming. The purpose of studying the method is to record each user's information, including user's name, machine's name, user's IP address, the time of modifying the file and etc. when he or she is operating an important file like confidential file, copyright file. By extracting the embedded information from the file, we can know that who modified the file, and when or where the file was modified. Thus, to some extent, the method plays the role of information tracking and copyright protection to the file.