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, [EMAIL PROTECTED]
PGP Fingerprint D454 E202 CBC8 40BF 3C85 B884 0ABE 4639
