From: Cerridwyn Llewyellyn <ceridwyn@wolfenet.com>
Date: Tue, 30 Jul 1996 20:56:38 +0800
To: cypherpunks@toad.com
Subject: Re: "privatizing" phones?
Message-ID: <2.2.32.19960730102239.006cc4b8@gonzo.wolfenet.com>
MIME-Version: 1.0
Content-Type: text/plain



>> Even if they did change the frequency the call was on, 
>> it would be a simple matter to decode how the frequency
>> change was negotiated, and "follow" the call (also easily
>> accomplished with cellular calls).  Failing that, there is 
>> a very limited range of frequencies allocated for cordless 
>> fones, and simply re-scanning for the conversation is a 
>> trivial inconvenience. //cerridwyn//
>Most of those systems do also change the order of the transmitted data, and 
>that's not limited to a few possibilities. If it's digital, they usually 
>encrypt it (only weak, but hey, you normally have to find the key real 
>time!)

Right.  After posting that, I realized I forgot to specify I was only
referring to analog cordless/cell fones.  Digital is a bit of a different
story, as it requires more sophisticated equipment to decode.  Still not
secure though.  (right now it's simply obscure).  //cerridwyn//