[52112] in Cypherpunks
Re: Beat Remote Monitor Snooping?
daemon@ATHENA.MIT.EDU (Roger Williams)
Thu Mar 14 01:37:35 1996
Date: Thu, 14 Mar 96 01:28:02 -0500
From: Roger Williams <roger@coelacanth.com>
To: cypherpunks@toad.com
In-Reply-To: <Pine.SV4.3.91.960313223844.19338E-100000@larry.infi.net>
(message from Alan Horowitz on Wed, 13 Mar 1996 22:46:01 -0500 (EST))
>>>>> Alan Horowitz <alanh@infi.net> writes:
> Visual contrast is not the same thing as frequency diffrence. It
> is quite easy to measure extremely small changes of phase.
Apropos of *what*?! If it was an NTSC colour TV; yes, you could
measure the colour by the phase of the 3.579 colour burst. But modern
computer monitors (i.e. VGA) don't represent colour that way at all --
they use separate red, green, and blue video signals. And the
original poster is correct -- it is extremely difficult to determine
which guns are generating any given pixel, using van Eck monitoring.
The only com/mil ELINT demo I've ever seen of a VGA monitor generated a
greyscale display.
> Nice try, but no cigar.
If the shoe fits...
--
Roger Williams PGP key available from PGP public keyservers
Coelacanth Engineering consulting & turnkey product development
Middleborough, MA wireless * DSP-based instrumentation * ATE
tel +1 508 947-8049 * fax +1 508 947-9118 * http://www.coelacanth.com/
