From: Mike Markley <mmarkley@microsoft.com>
Date: Tue, 5 Jul 94 10:24:01 PDT
To: cypherpunks@toad.com
Subject: RE: (None)
Message-ID: <9407051625.AA17615@netmail2.microsoft.com>
MIME-Version: 1.0
Content-Type: text/plain


----------
| From: Jeff Gostin  <jgostin@eternal.pha.pa.us>
| To:  <cypherpunks@toad.com>
| Subject: (None)
| Date: Sunday, July 03, 1994 4:08PM
|
| bmorris@netcom.com (Bob MorrisG) writes:
|
| > I've heard rumors through the years that CIA/NSA/whoever can aim a
| > parabolic antenna at your window, read the electronic pulses surrounding
| > your computer, and thusly determine what you are typing.  Is there any
| > truth to this?
|      If this is a reference to the TEMPEST attack, yes, they can. From
| what I hear, it's trivially easy for them to do, because they have The
| Right Equipment. Rumor also suggests that that The Right Equipment isn't
| so difficult to come by. I don't pretend to understand the intricacies of
| TEMPEST, but I do know that the government requires all of their computers
| (used at any level of security above none) to be TEMPEST shielded. This
| tells us its a real concern.
|
|      There are other ways to beat TEMPEST, like making it damn near
| impossible to get close enough to the computer in question to get a
| reading.
|
|                                         --Jeff
| --
| ======  ======    +----------------jgostin@eternal.pha.pa.us----------------+
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|

How well does a Tempest attack work with multiple machines in the same 
room? It seems to me that it would take additional equipment to filter 
out the different machines that are being run. It also seems that it 
should be trivial to create a noise generator that would make Tempest 
useless. Kind of like using a spark plug to foil older radar guns.

Mike.
=====================================================

Mike Markley <mmarkley@microsoft.com>

I'm not a Microsoft spokesperson. All opinions expressed
here are mine.
=====================================================