Development and implementation of text watermarking and information hiding technique

Abstract

The digital representation of text, audio, image and video documents has become very popular in the last decade. The success of digital technology is largely due to the capabilities of efficient transmission, storage, and perfect copying. However, especially the last feature leads to severe problems because unauthorized copying is also simplified. One approach to combat this problem is to mark a digital document such that a copyright can be proven or the distribution path be traced. "Digital Watermarking" means embedding information into multimedia data that should be imperceptible but irremovable. Thus, in contrast to copyright information included in the header of the data streams, embedded watermarks remain in the document even after format conversions or D/A and A/D conversions.There are numerous applications of digital watermarking such as copyright protection, copy protection, content authentication, transaction tracking and broadcast monitoring. Information hiding or steganography is related to watermarking but watermarking has the additional notion of being robust against attacks and having concern for not only the watermark but also the cover. In this project a watermarking algorithm has been developed and implemented which slightly modifies inter-word spaces so that different lines across a text act as sampling points of a sine wave. The method not only embeds a watermark but also hides information through the watermark thus providing a robust and imperceptible way for steganography through text images. Preliminary experiments have shown promising results.