PDF files become very popular nowadays. People use them to exchange information on the Internet, and so it is also a good choice to use PDF files as cover media for covert communication. A method for this purpose by two new data hiding techniques is proposed. The first is a technique based on a white space coding using spaceequivalent codes in the PDF file. And the second is a
technique of inserting invisible texts into PDF files via the use of artificially created text matrices outside the visible area of the displayed PDF document. A secret key is used to enhance the security of the embedded data.
Experimental results show the feasibility of the proposed ethod.
Relation:
Proceedings of 2009 Conference on Computer Vision, Graphics and Image Processing, Nantou, Taiwan, Republic of China
