From: Steve Mynott <steve@tightrope.demon.co.uk>
Date: Tue, 10 Feb 1998 17:59:05 +0800
To: Lucky Green <die@die.com>
Subject: Re: SOFT TEMPEST (fwd)
In-Reply-To: <19980209235936.37986@die.com>
Message-ID: <19980210095845.47535@tightrope.demon.co.uk>
MIME-Version: 1.0
Content-Type: text/plain



On Tue, Feb 10, 1998 at 06:46:55AM +0100, Lucky Green wrote:

> There wasn't a single person watching said demonstration in that brutally
> hot tent at HIP'97 that didn't walk away impressed. And I can off the top
> of my head come up with a design that would improve the gain by at least
> 20dB over what was used there..

I wasn't impressed.

That main tent was an old circus tent and was huge with enough room for
one thousand people.  Unfortunately it had the effect of focusing and
amplifying the already excessive heat on the sweating and dehydrated
victims sitting in it.  By the final day an attempt had been made to
open it up a bit more and to spray cold water on it.

The first thing I saw was a demonstration of the "Van Eck effect".
The idea was to pick up the screen display of someone's monitor at a
distance to read the information off it.  The lecturer was a German
professor and spoke heavily accented English.  He was very much as a
German professor might be shown in a film.  He spoke a lot about "Ze
Incriminating Emissions", which seemed rather funny at the time.

He had an aerial, which looked like an unconvincing Dr Who prop,
attached to a standard TV.  The circus tent atmosphere led somehow
to the impression that he was a stage magician performing tricks.
Also the audience's habit of cheering after each trick didn't help.
On the target PC screen were a few words in a very large font and he was
able to display this up on the TV.  He also put a device around the power
 supply lead and could pick up a better picture this way.  There were
mutterings from the audience, many of whom seemed unimpressed.  At the
question session the poor chap got a rather hard ride.  The gist of it
being "What we have been shown is twenty years old, there are modern
digital techniques that are much better".  His reply was "They are very
expensive and we have only just got the equipment and the results aren't
finished yet."  The counter measures were Tempest shielding.

In short if your password is visible on your monitor in letters three
inches high and there is a van outside your office with a large aerial
and German plates this might mean trouble.  Or maybe the NSA can pick
 it up anyway from America using the "newer techniques".


-- 
Steve Mynott
"no man or group of men shall aggress upon the person or property of anyone
else."  -- Murray N. Rothbard