From: Peter Wayner <pcw@access.digex.net>
Date: Thu, 24 Jun 93 14:57:27 PDT
To: cypherpunks@toad.com
Subject: Karn's note...
Message-ID: <199306242157.AA26979@access.digex.net>
MIME-Version: 1.0
Content-Type: text/plain



On Over-the-air encryption...

If anyone wants to read Tom Clancy's latest book, _Clear and Present Danger_
about a set of covert operations against drug kingpins in South America,
they will note that he mentions a magic box that will scan the airwaves
for voices on the cellular channels. This allows the protagonists to 
follow the conversations of the kingpins as they hop from limo to limo
using a different phone with each conversation. 

Does TriggerFish do this? 

My theory is that the 260-bit repeated XOR code was proffered because
it wouldn't interfere with algorithms that were doing simultaneous
voice recoginition. It is, after all, just the equivalence of doing
a discrete convolution across the signal. I believe that this should
be easy to handle with a few clever signal processing algorithms designed
for noise reduction. I don't know this with any stretch of confidence
so I would like to be disabused of this idea if it's harder than
all of that. 

--Peter