[OT] Combinatronics WAS Re: /dev/random and linux security issues (kinda long)

[aluminumsulfate at earthlink.net]

   From: "David Ecklein" <dave at diacad.com>
   Cc: <gnhlug-discuss at mail.gnhlug.org>
   Date: Sun, 15 May 2005 21:49:06 -0400

   My 2 cents worth...

   In my wasted youth I experimented with random number generator algorithms of
   various kinds.  One amusing but useful tool that can act as a fairly good
   eliminator of many such schemes is to convert the output into a graphical
   plot.  It often doesn't matter too much how this is done, just that the x/y
   position of a pixel is related somehow to the digital output of the scheme.
   You will be surprised to see that many purportedly random series of
   characters or numbers that look good will show regular and obvious patterns
   when so displayed.  Sometimes these patterns take some scaling in time and
   space to become obvious.

Sometimes, viewing your plots in a different number of dimensions will
reveal underlying patterns, too.  A pattern may not be visible in two
dimensions, but be easily visible in 3D.

I should give this plotting thing a try with /dev/random and see if
any inhomogeneities emerge. (Oh, No! I can hear the list saying... :)
It's about time for me to review my gnuplot syntax, anyway.

   For a "truly random" source, it might be best to use a good white noise
   source, such as a properly chosen and biased point contact silicon diode or
   the like.  For something in between and completely accessible to a software
   approach, the computer clock could be factored into a prospective algorithm.

A point contact what??  Info on this would be welcome.  Any links on
how to build one/attach it to Linux?  I was thinking of hooking up an
AM radio to my sound card, tuning in some static, hitting record, and
post-processing the results.  Other ideas I had included running edge
detection algorithms on pictures of cooked rice, hooking some kind of
scintillation detector to a radiation source (like a smoke detector),
and measuring the interval between barks of my neighbor's (annoying)
dog.

Maybe, if one side of a coin were blackened and the other side made
reflective, one of those EMP coin flippers could be hooked up to a
parallel port....

Dave