From: tcmay@got.net (Timothy C. May)
Date: Sun, 30 Jun 1996 16:22:02 +0800
To: cypherpunks@toad.com
Subject: Re: Hardware RNG
Message-ID: <adfb5d610a0210048597@[205.199.118.202]>
MIME-Version: 1.0
Content-Type: text/plain


At 1:26 AM 6/30/96, Jack Mott wrote:
>I just recently built a hardware RNG, I just wanted to see what you guys
>think of it, here is how it works:
>
>        Got a geiger counter plugged into the game port

>any thoughts? It seems to work well, no basic stat analysis reveals any
>pattern, and physicists have backed me up on radioactive decay being
>'the great randomizer'.

First, have fun playing with it. Second, watch out for subtle statistical
biases.

While radioactive decay is unpredictable (so are a lot of things, by the
way), there are all kinds of biases that reduce the apparent entropy.
Detector "dead time" is a classic one (basically, the detector can't detect
counts during a post-pulse recovery time...probably not a problem at low
count rates, but an example of how subtle things can sneak in).

--Tim May

Boycott "Big Brother Inside" software!
We got computers, we're tapping phone lines, we know that that ain't allowed.
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