The Security Breach
Steganography simply takes one piece of information and hides it within another. Computer files (images, sound recordings, even disks) contain unused or insignificant areas of data. Steganography takes advantage of these unused areas by replacing them with information (encrypted mail, for instance). The files can then be accessed and exchanged without anyone knowing what really is inside them. An image of a supermodel might contain a private letter to a friend. A wave file might contain your company's entire personnel roster and their files, or even the plans for your telecommunications network.
Both the creation of a clandestine message and the code to open it can easily be accomplished through steganography software that's relatively simple to obtain and use. With steganography, the clandestine user can take advantage of the millions of new audio and image files posted on the Internet every day, posting his message in the sea of files that exist on the web.
Here's how it works.
An image, whether a picture or a graphic, is represented by a series of dots. The image could look simply like a photograph exchanged between two friends or family members. Inside the dots of the image are a string of letters and numbers that computers read to create the image. A coded message or an image can be hidden in those letters and numbers by using free encryption Internet programs and locations set up by privacy advocacy groups on the Net. These programs scramble the messages or pictures into images that can only be unlocked using a private key (or code) selected by the recipient.
U.S. officials concede that it's difficult to intercept, let alone find encrypted messages and images on the Internet's estimated 28 billion images and 2 billion web sites. Even if they find it, the encrypted message or image is impossible to read without cracking the encryption's code. A senior Defense Department mathematician says that cracking a code often requires an inordinate amount of time and the use of a government supercomputer.