Research And Design On XML Digital Watermarking Based On Data Usability

As the development of network technology, people in computer field have been paying more and more attentions to XML(eXtensible Markup Language). Simply speaking XML norm is group of rules defined by W3C (World Wide Web Consortium) and used to describe structured data by general text. As a method for describing data having nothing to do with platform, XML has become a fact criterion of data exchange on Internet.With the rapid development of E-business and E-government, more and more valuable data are exchanged or stored by XML. Since XML document belongs to text file, it is convenient to copy, thus, a large number of XML documents are in danger of illegal copy and distribution. So, it is urgent to protect the copyright of XML documents.XML digital watermarking technology is an efficient means in which XML documents can be free of illegal copy and distribution. Because XML document is semi-structured, it can be denoted as the form of diagram or tree, with structure or data digital watermarking technology based on XML can embed watermark into document. The existing digital watermarking technology may embed information into document by modifying document structure and description manner, as well as by the combination of structure and data. Such as Wilfred Ng et al. present a new method for embedding watermark in the XML document storing numerical data, however, what it has imbedded into the document is one-bit watermark.To improve the one-bit watermark algorithm, in line with data usability, a new digital watermarking algorithm is put forward in this paper. By introducing a few of errors at the digital of the most unimportance of the decided numerical data in XML document and replacing the lowest digital with the watermark bit, watermark can be embedded into the XML document. Watermark can identify such information as document author and the copyright of series and adopt the majority rule to ensure the robustness of the presented algorithm.Thus, XML watermarking system based on data usability is realized, moreover, this paper experiments on the invisibility and robustness of the XML document into which the watermark is embedded. The experimental results reveal that the presented algorithm is effective in guaranteeing the usability and robustness of data in XML document, and, the embedded watermark can be immunized from such attacking methods as the additive and deletion of data.