From: "Geoffrey C. Grabow" <gcg@pb.net>
Date: Tue, 30 Jul 1996 02:53:50 +0800
To: Remo Pini <rp@rpini.com>
Subject: Re: "privatizing" phones?
Message-ID: <2.2.32.19960729151349.006e8264@mail.pb.net>
MIME-Version: 1.0
Content-Type: text/plain


At 12:26 07/28/96 +0200, Remo Pini wrote:
>-----BEGIN PGP SIGNED MESSAGE-----
>
>To: cypherpunks@toad.com
>Date: Sun Jul 28 12:24:57 1996
>> 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!)
>>
The key doesn't need to be found in real time!  You can always record the
call and decrypt it later.  If the information deals with an event in the
future, you could have plenty of time to crack it.
 
                                                     G.C.G.