An Erasable Watermarking Scheme Based on Text Exact Authentication

It is becoming easier and easier to tamper with digital Works in ways that are difficult to detect. The problem of authentication has been well studied. This paper proposes a novel erasable text watermarking scheme for exact authentication, which including authentication of content and format of Chinese Word documents. In this method, the cover document is divided into two blocks by utilizing the mathematical expression of Chinese characters, and then the hashing values of the text document’s content and format are embedded into the two blocks respectively by setting underlines to Chinese characters and hiding the underlines. In each block, the embedding position is chosen by Chinese character’s strokes and the magic square. Watermark to be authenticated can be extracted without the help of the original watermark and Word document itself. When any modification of the watermarked text document’s content and/or format are made, the Chinese text document will fail to pass the authentication. Experimental results indicate that the proposed scheme is efficient and secure.