[4686] in cryptography@c2.net mail archive
Re: Xerox supplies stego?
daemon@ATHENA.MIT.EDU (Bill Stewart)
Tue May 11 21:05:25 1999
Date: Tue, 11 May 1999 16:22:40 -0700
To: "Brown, R Ken" <brownrk1@texaco.com>, cryptography@c2.net
From: Bill Stewart <bill.stewart@pobox.com>
In-Reply-To: <1A2B916673DFD211ABC700805FA7AA68990033@MSX11002>
At 08:34 AM 3/22/99 -0600, Brown, R Ken wrote:
>Probably not news to most of you, but I didn't realise they did this sort of
>thing.
>http://www.xerox.com/xsis/dataglph.htm
The basic intent of the system is watermarking, rather than stego in general -
you can hand somebody a paper copy of your document, marked for them,
and if you later encounter a Xerox copy, you know whose original it was.
>
>[...]
>
>"DataGlyph technology allows ordinary business documents to carry thousands
>of characters of information hidden in these unobtrusive gray patterns that
>can appear as backgrounds, shading patterns or conventional graphic design
>elements. Often, their presence will go completely unnoticed. "
>[...]
>"As a final step, the bytes of data are randomly dispersed across the glyph
>area, so that if any part of the glyph area on the paper is severely
>damaged, the damage to any individual block of data will be slight, and
>thus easy for the error correcting code to recover. Together, error
>correction and randomization provide very high levels of reliability, even
>when the glyph area is impaired by ink marks, staples and other kinds
>ofimage damage."
Thanks!
Bill
Bill Stewart, bill.stewart@pobox.com
PGP Fingerprint D454 E202 CBC8 40BF 3C85 B884 0ABE 4639
