From: Philippe Nave <pdn@msmail.dr.att.com>
Date: Tue, 12 Jul 94 07:39:30 PDT
To: Cypherpunks <cypherpunks@toad.com>
Subject: RE: Modems that variate speed
Message-ID: <2E22A8EF@mspost.dr.att.com>
MIME-Version: 1.0
Content-Type: text/plain



Sorry I can't attribute the quote properly; Microsloth Mail strikes
again...

> [modems that change speed in mid-transmission proposed as a
>  defense against wiretap]
>
> Aaron

This would probably thwart someone trying to tap the data stream
in real time, assuming that the speed changes caught the snooper
by surprise, but I don't think that real-time data traps are the
real problem. Someone who went to the effort of listening in on
your transmission would probably record the whole session on
tape; then, they could map the speed changes and pick up all the
data at their leisure later on. I would speculate that a really
good DAT deck could record the modem session well enough to give
your opponent all the time he needs to figure out the speed shifts
and pick up the data.

   -Philippe