Re: [dvd-discuss] STEGANOGRAPHY - Veiled Messages of Terrorists May Lurk in Cyberspace

[Tom <tom(at)lemuria.org>]

On Tue, Oct 30, 2001 at 09:08:00AM -0800, Michael.A.Rolenz@aero.org wrote:
> image or music. Those who are starting to look for such deviations say 
> that
> their programs are as yet imperfect but that, nonetheless, some are 
> finding
> widespread use of steganography on the Internet. For national security
> reasons some of these experts do not want to reveal exactly what they 
> find,
> and where.

Weird, isn't it? Just a month prior to the terrorist attacks, Niels
Provos held a lecture at HAL2001 where he revealed that he had scanned
2 million pictures downloaded from the web and found, essentially,
nothing.

> Mr. Hosmer says his company has not decided whether to reveal all the 
> sites
> where he is finding steganography. He has found it on the auction site 
> eBay,
> where people can post pictures anonymously, inserting hidden messages if
> they choose to, and just as anonymously download them, retrieving the
> messages. WetStone works under a contract to the Air Force.

More weirdness still - ebay was the very site that Niels had used in
his study.

Contrary to this "expert", Niels made a true scientific study. Most
importantly, he revealed his methods, allowing others to verify his
claims.


> One limitation in published steganography detection programs is that often
> they miss images hidden in the most frequently used format, JPEG, said Dr.
> Jessica Fridrich, a research professor at the Center for Intelligent 
> Systems
> at the State University of New York at Binghamton.
> 
> It is hard to see evidence of steganography in such files because the
> detection methods look for statistical evidence that an image's data have
> been distorted. But JPEG files are distorted by their very nature - the
> digital data are altered when the files are compressed to send them
> electronically.

5+ years ago, that would have been true. Today, however, both the
well-known stego and the well-known detection tools all support jpeg -
often exclusively.



> Of course, those whose business it is to intercept terrorist 
> communications
> would never reveal anything they have learned about steganography.

Maybe that's why they are so far behind.


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