A Fragile Watermarking Scheme Based on SVD for Web Pages

With the development of the Internet, more and more people concern the protection of web pages. Fragile watermarking technique is an effective method for solving the tamper-proof of web pages. In this paper, a fragile watermarking scheme based on singular value decomposition (SVD) for web pages is proposed. First of all, a model utilizing the frequency of letters is used to denote a web page, and the web page is expressed as a matrix through this model. Afterwards, we take SVD transformation on the matrix and extract its singular values to generate watermarks. Finally, the watermarks are embedded into the letters of HTML tags by altering the upper and lower cases of letters, simultaneously, they are embedded into the embedding locations controlled by a secret key. In the detection procedure, whether a web page has been tampered or not can be judged effectively only by comparing the generated watermarks with the extracted watermarks. The experiment shows that the proposed scheme has stronger abilities to identify the types of modifications and to locate the locations of modifications.