Steganography in its more low-tech forms has been around for centuries. The term, derived from Greek, means 'covered writing'. One of the more inventive versions is a way ancient Greeks would send a secret message over long distances. They'd shave the head of a messenger, tattoo the information on his scalp, wait until his hair grew out then send him on his way.

Later societies came up with null ciphers. You'd write an innocuous-looking note that itself held a message.

During World War II, the Germans developed microdots, which shrunk a photograph down to the size of a period on a sentence. A simple postcard could carry dozens of microdots.

Now the varieties are endless. MP3Stego compresses the hidden message into an MP3 music file's bit stream, so the message comes out as the song plays ? provided, of course, that you have the key.

Hundreds of steganography software programs are available for free on the Web. They include JSteg Shell, MP3Stego, DriveCrypt and Contraband Hell Edition. Steganography is one of those things that hackers like to play with and put out there for the public. It's their version of stamp collecting.

www.usatoday.com/tech/columnist/2001/12/19/maney.htm

Last edited on 2005.03.06 16:11