A Text Watermarking Algorithm Based On The Conversion Of Character Format And Interpunction

In order to protect copyright of digital products and prevent piracy, a technology--digital watermarking is proposed. With the regard to the fact that digital watermarking research mainly focuses on image, video and audio, But the studies on Document Watermark are not as great in amount or quantity. In fact, however, in some cases, it is more essential to verify the authenticity and integrity of text documents.This paper mainly investigate WORD document watermark algorithm. Based on the analysis of existing digital document watermarking algorithms, two new document watermarking algorithm are presented. The two algorithms can be used mainly to identifying tamper in the document and authenticate the integrality of the document.The first algorithm is character-based watermarking algorithm for document. Integrating the principle of Telecommunication, using the theory of encryption to protect watermark code. Watermark is embedded by modifying the shape and color of WORD document. The experiment uses the watermarking software that based on VBA. Simulation results show that this algorithm not only has high security, but also can enhance the capability of watermarking.The second algorithm is interpunction-based watermarking algorithm for document, in which the watermark is embedded by modifying the interpunction of document. Watermark code is produced by using the error control theory. Do a lot of experiments on embedding, extracting and attacking the watermarking. Experimental results show our algorithm is strong enough to resist common processing and our algorithm can enhance the security of documents and watermark's capacity.