Re: Toaster to Generate Random Numbers

From: Barry Margolin (barmar@genuity.net)
Date: 01/17/03 

From: Barry Margolin <barmar@genuity.net>
Date: Fri, 17 Jan 2003 16:25:43 GMT

In article <b07i5h$f05$1@nntp.itservices.ubc.ca>,
Bill Unruh <unruh@string.physics.ubc.ca> wrote:
>No. Depending on the physical model and measuring apparatus, low order
>bits can also be correlated and biased. I do not think in this game
>there is ever some magic bullet, which always works. Understand your
>random source, and use that understanding to develop a good generator.

I doubt that any physical process could have correlations at the very low
orders, unless it's correlated at the quantum level (the finest precision
that's possible to measure in the real world). However, I agree with you
that measuring devices may have biases that prevent them from accurately
reporting this data.

In fact, I suppose that any A-D converter *must* have such a flaw. If the
analog data below the lowest bit is exactly (to the extent that the device
can measure it) halfway between the values, it has to have a rule to round
it one way or the other, and that rule produces a bias of some kind. 

-- 
Barry Margolin, barmar@genuity.net
Genuity, Woburn, MA
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