Look closely; the picture may tell a story, Ben Berkowitz, USA Today

Publish Date:

June 30, 2004

LOS ANGELES - The adage that a picture is worth 1,000 words still holds, but look very carefully that same picture may also contain an illicit love note, a recipe for bomb-making or the secret location of buried treasure. In a world where invasion of privacy is increasingly commonplace, the technique called steganography is a relatively easy-to-use method of hiding messages and files a method that, some say, is most often used for nefarious purposes.

Steganography, as defined in Webster's Dictionary, is "the art of writing in cipher, or in characters which are not intelligible except to persons who have the key."

More broadly, though, it has come to mean the practice of hiding messages in picture or music files in such a way that they do not change the look or sound of the "carrier."

But making use of the technique does not require a Ph.D. in mathematics or shady contacts in the technology underworld. Steganographic software is readily available on the Internet, some of it free.

"Steganography has one big advantage ? that is you cannot prove that information exists. If you just use encryption, you will always see that there is a file that carries encrypted information," said Fabian Hansmann, chief executive of Steganos, the German software maker.

Steganos sells a $60 security software suite that includes a program for embedding data in media files, as well as encrypting and password-protecting that data.

But Hansmann admitted that for most users, steganography is more than they want or need. Instead, he said it is more of a "paranoid option" for the advanced user who has the time and interest to hide their data.

Old practices made new

Experts say the term steganography was coined more than 500 years ago, but they date the actual practice of hiding messages in and on other media as being thousands of years old.

In a recent paper in the FBI Laboratory's journal Forensic Science Communications, Gary Kessler, a professor at Champlain College in Vermont, said it was common in history for messages to be "hidden on the back of wax writing tables, written on the stomachs of rabbits, or tattooed on the scalp of slaves."

But laws forbidding slavery and cruelty to animals, combined with the practical nature of the times, have made those methods unworkable ? leaving as the best option advanced steganographic software like Steganos, or free programs like S-Tools, Camera/Shy and MP3Stego, among others.

One Web site devoted to the technology, StegoArchive.com, offers a $21.95 CD, along with more than 125 free and commercial steganographic programs.

Yet, there are those who believe that, by and large, the technology is being used mainly for criminal purposes. Reports surfaced not long after the attacks of Sept. 11, 2001, of purported use by terror organizations of steganography to hide messages in pornographic images.

"One of the concerns with steganography is that it's a covert channel for terrorists around the world," said Ralph Echemendia, who teaches a hacking boot-camp to corporate security professionals across the country for Intense School, a Florida-based company.

And, Hansmann said that his Steganos products are under constant scrutiny by law enforcement officials.

"We regularly have inquiries from government agencies of all kinds, from foreign secret services to local police departments in Germany," he said.

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