A Novel Approach to Digital Watermarking for Vietnamese Documents

Van Doan Nguyen
Faculty of CSE, HCMUT, Vietnam

Tran Khanh Dang
Faculty of CSE, HCMUT, Vietnam

Nguyen Thanh Son
Faculty of CSE, HCMUT, Vietnam

Abstract
In this paper, we propose a novel approach to digital watermarking for Vietnamese documents. The target documents need to be converted to Post-Script format files before embedding information. Security information is em-bedded into the documents by shifting up or down a small gap of Vietnamese signs, which are special to Vietnamese documents. This embedded information can be used for copyright protection or tampering detection. The watermarked document will be converted to PDF format, containing only images instead of texts, before being published. During the detection phase, our approach does not need original documents in order to recover the watermarks. Theoretical analyses and empirical experiments show the efficiency and effectiveness of our proposed solution.