Introduction to Steganography
One purpose of hijacking a system is to allow clandestine operatives to use established communications vehicles for secret communication. One example of systems hijacking is steganography, which literally means "covered writing," and dates back to ancient Greek times. Steganography is the art and science of hiding the fact that communication is happening. It involves hiding messages inside text, images, sounds, or other binary files for clandestine communications.
Steganography attempts to hide a message in such a way that an outside observer may not realize that a message is being communicated. Unlike encryption, steganography cannot be detected easily. Now that this ancient technique has been applied to modern communications systems, it has become a very effective form of sending undetectable messagesand possibly a valuable tool for cyberterrorists.