From: George A. Gleason <gg@well.sf.ca.us>
Date: Wed, 14 Apr 93 03:20:16 PDT
To: ebrandt@jarthur.Claremont.EDU
Subject: Re: Encrypted Cordless phones
Message-ID: <199304141019.AA21841@well.sf.ca.us>
MIME-Version: 1.0
Content-Type: text/plain


And also.... Radio Shack just entered the market with a cordless which uses
frequency inversion.  That's analog...  Probably can be broken in less than
a minute, even by amateurs who know how to solder.   About 1986 or so, a
certain state agency ordered some expensive walkie-talkies which were
supposed to be secure against protesters with scanners.  Guess what?  Analog
frequency inversion.  

And in fact, with a little practice, you can listen to inverted speech
directly and make sense of it.