Research On Word-shifting Coding Text Watermarking

Digital watermark is an emerging research field. With the developing of E-commerce and E-politics, documents transmission of governments and enterprises will be gradually put on network. A large number of important documents related to national security, commercial confidentiality and personal privileged information would be transmitted through network. Safeguarding of these documents is a matter of safety insurance of individuals, groups and even a country's development. Therefore, research of text watermark is crucial and urgent. However, digital text not containing redundant information to conceal confidential information, embeds watermark in text is much more difficult than in digital image, audio, video documents. The current text watermarking algorithm mainly contains the line-shifting coding, word-shifting coding, modifying characteristics of the words, and analyzing text semantic, etc., among which the word-shifting coding text watermarking is being widely used for its high capacity and robustness.Based on theories of digital watermarking research methods and technologies, this paper is focused on word-shifting coding text watermarking with main studies as below:(1) Proposes a word-shifting coding blind text watermarking algorithm. In contrast with the traditional non-blind algorithm, this proposed method is much easier in application.(2) Analyses the "an anti-analog domain attacks text watermarking algorithm", which is proposed by our laboratory. Summarizes its characteristics; improves the deficiency; enhances the capacity and robustness.(3) Proposes a binary algorithm based on the mathematical morphology. Applied in the pre-processing of text image, it ensures the text image's visual quality and enhances the capacity.(4) Designs and implements a source investigation text watermarking system for safeguard of E-commerce and E-politics texts, which has been put into practical application. Focusing on the text watermarking, the system embeds the legitimate receiver's identity information into distribution texts, when intercepts the watermarking text image, extracts the watermark to provide the reliable evidence. The system design, implementation and application make the text watermarking more familiar and easily acceptable to the people, and promote the application process of the text watermarkingtechnology.