Research On Technology Of The Multiple Digital Watermarking About Word Text

At present, digital products appear in nearly all areas of life, which can be seen that thedigital texts have become integral to many tasks and transfer of information, Moreimportantly, popular office software Word provides us with a convenient platform. When thepeople enjoy the high efficiency of software Word, Word text is easily modified, copied,transmitted at the same time. Therefore, how to protect the content of the text not to bedistorted and spread illegally are needed to be solved urgently. In recent years, with the rapiddevelopment of electronic commerce, various departments and units, enterprises andorganizations have a considerable amount of text materials which are needed to be transmittedthrough the network rapidly, especially the electronic mail, confidential information,electronic contracts. If necessary protective measures are not taken to these important texts,the text data will be easily edited and revised, with the consequence that the content modifiedis likely to affect such important aspects as the national security and evidence-providing to thecourt. Consequently, the research on how to ensure the security of text is a vital and urgenttask.This thesis first introduces the concept of text digital watermarking, and then itscharacteristics, classification and typical models are described. Then further research isinvolved in human visual system model, cryptology, MD5algorithm and Word object model.When the research on the text digital watermarking algorithm and the protection oftextual copyright are carried out, the methods taken are unitary, thus there is no way toprovide multiple protection simultaneously. Based on this disadvantage, digital watermarkingalgorithm based on multiple text technology is put forward. At first, the algorithm of activizedtext digital watermarking model and distribution-related watermarking embedded algorithmare proposed. Then the algorithm of multiple textual watermarking are divided into two parts:On the one hand, guided by the principle of human visual effect, according to thecorresponding attribute of Word document, to embed multiple digital watermarking bygrouping each character at specific distribution with specific value. First the text embeddedwatermark information memory MD5algorithm is processed with two groups of thewatermark insertion point, from the positive and reverse directions in processing embedded watermark. When watermark is attacked, it can recover distribution-relatedly. Secondly, todeal with textual watermark by combing the attributes of Word document with zerowatermark and timestamping method. Because Word document has the property of describingthe unique features of each specific document, we can apply this feature, and then makeprocess on the feature with zero watermark method. Finally, to timestamp, in order to ensurethe copyright validity of watermark. We draw the conclusion that this algorithm can identifyand protect effectively the copyright of the Word document watermarking with the advantagesof anti-attack and robustness.