From: Douglas Sinclair <dsinclai@acs.ucalgary.ca>
Date: Wed, 27 Jan 93 05:37:20 PST
To: cypherpunks@toad.com
Subject: Random OTP sources
Message-ID: <9301271305.AA25910@acs1.acs.ucalgary.ca>
MIME-Version: 1.0
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Much discussion has been going on about creating a truly random OTP key by tuning in to dead TV channels, etc.  There is a much simpler, and more secure way.   
Look at the decay of a small radioactive source.  Find a time period in which
there is a 50% chance of seeing an event, and then clock a 1 if you do, or a
0 of you don't.  Radioactive sources and detectors are easily obtained from
smoke detectors, and it should be fairly easy to set up (though I havn't done
it).  If our understanding of quantum mechanics are correct, the resulting 
bitstream is truly random.  RF noise may be random.  Also, if the NSA or
other Big Brother organization knows what you are doing, they can try listening
in on the same channel and deducing your key.  To my knowledge, there is no
way to see what is going on in a small Californium source if you have more
than a few meters between the source and detector.  Anyhow, a given event
will probably only produce one particle, or maybe two, so your point detector
will only see a portion of the events and knowledge of particles in another
direction doesn't tell you anything.

Hm.  I hope that was coherent.  Any comments?
-- 
Vercotti: I was terrified of him.  Everyone was terrified of Doug.  I've seen
          grown men pull their own heads off rather than see Doug.  Even
          Dinsdale was frightened of Doug.
Interviewer: What did he do?
Vercotti: He used sarcasm.  He knew all the tricks, dramatic irony,
          metaphor, bathos, puns, parody, litotes and satire.
			-- Monty Python, Episode 14
PGP 2.1 Key by finger