From: Petro <petro@playboy.com>
Date: Fri, 6 Nov 1998 02:43:03 +0800
To: Jim Choate <cypherpunks@einstein.ssz.com (Cypherpunks Distributed Remailer)
Subject: Re: TEMPEST laptops (fwd)
In-Reply-To: <199811050611.AAA10989@einstein.ssz.com>
Message-ID: <v0401170bb2677ca4c6a6@[206.189.103.230]>
MIME-Version: 1.0
Content-Type: text/plain



At 1:11 AM -0500 11/5/98, Jim Choate wrote:
>Forwarded message:
>> Date: Wed, 4 Nov 1998 21:45:29 -0800
>> From: Tim May <tcmay@got.net>
>> Subject: Re: TEMPEST laptops
>
>> Radio waves scatter...they don't just travel in pure line of sight. And
>> even if they travelled only in line of sight, the reflections from inside
>> the box and then into the room and then off surfaces....
>
>It depends on the frequency. Last time I checked a laser or a maser (both
>are radio waves strictly speaking) travel LOS. The scattering comes from
>beam divergence and incidental refractions and reflections from the
>molecules in the air and supported detritus.

	And both Lasers and Masers scatter under certain conditions. If you
can see the laser, it is scattering a bit of [energy light photons]

	That is what Mr. May is talking about.

	I was under the (apparently false) impression that things like
animal bodies, and ordinary building materials (like wood, Lathe &
plaster/drywall) wouldn't stop or significantly bounce the beams back the
way you didn't want them to go.

	I was thinking more of controling the direction of the RF, rather
than trying to completely supress it.

	It doesn't appear that will work.

>> Microwave ovens work by having the waves bounce around inside a box. Any
>> significant hole or crack (up to roughly half the wavelength) would let the
>> waves out.
>
>Depends on the size of the hole and location. In most microwave ovens there
>are definite dead-spots (corners and the exact center of the area are
>notorius).

	We're not cooking Hotdogs here, and we aren't using (for the most
part) microwaves. Yes, you can heat a hotdog on a PII, but that is more
from heat radiation than RF.

	Microwave ovens also leak RF.
--
"To sum up: The entire structure of antitrust statutes in this country is a
jumble of economic irrationality and ignorance. It is a product: (a) of a
gross misinterpretation of history, and (b) of rather nave, and certainly
unrealistic, economic theories." Alan Greenspan, "Anti-trust"
http://www.ecosystems.net/mgering/antitrust.html

Petro::E-Commerce Adminstrator::Playboy Ent. Inc.::petro@playboy.com