Schneier on Stego, Dead Drops, bin Laden

[Peter Wayner]

Schneier has never really cared much for
steganography and he seems to take every
opportunity to belittle it. In _Secrets and Lies_,
he argues that he's never received images in email
and so steganography will fail for lack of a
channel.

In any case, there are plenty of business uses of
whatever might be called steganography. The term
itself is difficult to pin down because it could
include many things that people do without
realizing that they're engaged in steganography.

Microsoft Office tags documents with the serial
number of the document creator. The creator and
everyone else who sees the document will never see
this number, but it's there. I think the serial
number is there to help them track down piracy and
copyright infringement.

The content creation companies from the music and
movie business are also big believers in
steganography. They hope the tool will allow them
to mix in copyright messages into digital copies.

The U.S. government has long explored ways to tag
documents, presumably to help track classified
information that might fall into the hands of
terrorists.

U.S. government agents in pursuit of terrorists
must often use steganography to communicate with
other agents. Hiding the message stream may be
the only way they can maintain their cover.

Lately the press has been focusing on the unproven
possibility that the terrorists may use steganography
to communicate. The complete story should include
how the technology is used against terrorism and digital
piracy.