Information Hiding for Text by Paraphrasing

Digital fingerprinting becomes paid growing attention as a technology resolving copyright problems. Previously, researchers have been only interested in image based digital fingerprinting where secret information is hidden in images, and text have not been the main target of hiding information. In this paper, we propose an information hiding method for text. Our information hiding method is based on paraphrasing that preserves the meaning. By paraphrasing or not, pieces of information are embedded. We experimentally evaluated the proposed method with Japanese manuals and user agreement forms of software, and found the paraphrased text, namely information hidden text, is preserving the meaning of original contents and very natural as language.