From: tcmay@got.net (Timothy C. May)
Date: Sun, 28 Apr 1996 07:06:40 +0800
To: cypherpunks@toad.com
Subject: Re: trusting the processor chip
Message-ID: <ada7a2f20102100497bb@[205.199.118.202]>
MIME-Version: 1.0
Content-Type: text/plain


First, there ain't no way that electromagnetic radiation is going to be
detected coming from the surface of a ULSI chip. Radiated power levels are
going to be in nanowatt or picowatt level from any one metal or poly line,
and of course will be undetectable at any distance. Not to mention the size
of the radiator implies inefficient launch of pulses (the lines are likely
to be rarely longer than a millimeter).


At 11:04 AM 4/27/96, David Lesher wrote:
(quoting someone else)
>> > More likely,I think, an organization like the NSA
>>       I thought that most (all?) chips already radiated on the
>> electromagnetic spectrum? Isn't that what tempest is about?

TEMPEST is not about emissions from the surface of a ULSI chip, for
example, but about the emissions (and controlling them, shielding them,
detecting them) from equipment in general.

Most of the "van Eck" radiation (so-called because he wrote the first major
public papers on this mode) comes from the deflection circuitry for CRTs,
where the radiated power levels (and lengths of radiating elements) are
considerably larger than what I mentioned above. It is the CRTs that mostly
cause problems.

The PCBs inside modern computers also emit wideband pulses, and this may be
detectable and usable to an adversary. Good shielding practice helps (those
little FCC stickers....). TEMPEST deals with suppressing the emission even
more.

>B) Sure the Fort has Fab facilities. But Acme Gas & Grocery fixes
>cars, yet they do NOT have the diagnostic computer for my [in my
>dreams..] new BMW.
>
>Preventium & leading edge chips requires MASSIVE amounts of
>money for the infrastructure, and yesterday's versions do not cut
>it. [Tim, got any real $$ here?] I suspect it's like monitors: 14"
>SVGA's cost $200; 16" $650; 19" $1200 & 21", don't ask. Sure,
>tomorrow the 16" is $500, but you need it TODAY.

I hate to say it, but all this stuff has been covered extensively in the
past, in the archives.

Yes, the NSA has its own wafer fab. Or, more precisely, the most recent
example I know of is that National Semiconductor accepted a contract to
build a fab at Fort Meade. This is not surprising, as the NSA is
responsible for supplying coding and ciphering materials to U.S. forces
worldwide, and so must generate ROMs, PLAs, and other special chips to
cipher machines around the world. Having the fab at the Fort helps
security.

(Sandia Labs also makes such gizmos for them, and has pretty good security,
I suspect.)

These wafer fabs are probably 1.25 micron fabs, far from the .35 micron
fabs now being used to make the 166 MHz Pentiums you can buy at Price Club.


--Tim May

Boycott "Big Brother Inside" software!
We got computers, we're tapping phone lines, we know that that ain't allowed.
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Timothy C. May              | Crypto Anarchy: encryption, digital money,
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