From: root%pig.jjm.com%jjmhome.jjm.com@jjmhome (0000-Super User(0000))
Date: Sun, 3 Jul 94 22:00:27 PDT
To: cdodhner@indirect.com (Special Agent Thomas Johnson - NSA)
Subject: Re: TEMPEST jamming possible?
In-Reply-To: <Pine.3.89.9407032026.B13473-0100000@id1.indirect.com>
Message-ID: <9407040458.AA04284@pig.jjm.com>
MIME-Version: 1.0
Content-Type: text/plain


> 
> On Sun, 3 Jul 1994, Jeff Gostin wrote:
> 
> Or could it be possible to put out enough 'garbage' radiation to throw 
> them off? it seems to me that if you knew which frequencies to use, you 
> could blast out cryptographicly random white radio noise which would make 
> it imposible to determine what was 'good stuff'. Basicly the concept is 
> to encrypt all of your wasted radiation with a one-time pad, and throw 
> away the keys.

	Yes you can jam TEMPEST detection systems.   Since many of them
use correlation detection technology to extract weak repetitive signals
from uncorrellated hash, you had better radiate coherent garbage
rather than just lots of noise, since the processing gain of the coherence
can be rather large (tens of db or more).

						Dave Emery