From: "Perry E. Metzger" <perry@piermont.com>
Date: Fri, 3 Nov 1995 22:50:05 +0800
To: tcmay@got.net (Timothy C. May)
Subject: Re: Sources of randomness
In-Reply-To: <acbf085205021004e36c@[205.199.118.202]>
Message-ID: <199511031427.JAA08758@jekyll.piermont.com>
MIME-Version: 1.0
Content-Type: text/plain



Timothy C. May writes:
> I meant a t.v. channel, as in broadcast t.v., such as is easily gotten with
> rabbit ears, or nothing (since the idea is to get noise, from the ether, or
> from the tuner itself). A snow-filled picture has pixels which are unlikely
> in the extreme to be predicted/deduced by outside attackers, who cannot
> know the details of antenna orientation, microscopic variations in
> geometry, LRC, tuner sensitivity, etc. That is, snowy pictures are not
> guessable.

I'm not so sure. There may be hidden patterns we don't notice. Its on
little things like this that a cryptanalyst would try to pry open a
hole in a system. I'm unwilling to predict that the patterns are
unguessable based purely on gut instinct. As Bob Morris of the NSA has
said, never underestimate the effort your advesary will go to in order
to read your traffic.

I'll stick to recommending radioactive sources for now. Quantum
mechanics is your friend, and detectors from places like Aware are
cheap.

Perry