From: jerry@terminus.dell.com (Jeremy Porter)
Date: Sat, 25 Dec 93 13:16:43 PST
To: cypherpunks@toad.com (cypher)
Subject: Random numbers again
Message-ID: <9312252113.AA05269@terminus.us.dell.com>
MIME-Version: 1.0
Content-Type: text/plain


Well, I've finished my prototype version of my hardware random number
generator.  According to preliminary work the numbers are truely random and
evenly distributed.  The circuit plugs into the parallel port(bi-directional
mode) and presents 8 bits of data on the data lines.  You can
quickly generate 10k bytes of data with this device.
	I am intrested in hearing from anyone that wishes to take
a look at some data to measure the randomness of the data.  If anyone
is interested I will provide two sets of data, one from my random number
generator and one from a pseudo-random number generator.
	The circuit uses some 555based timers and some RC networks.  A lot
of people will not believe that this circuit is truely random, but it works
out to be, under some conditions.  It boils down using two variable,
independent, periodic functions to generate one bit.  Due to temperature
effects, oscillator stability, circuit noise, and some other factors,
the error in frequency and phase of the two oscillators is larger effect
than the measurable characteristics of the circuit.  In this circuit,
I use the 555 timers as the oscillators (with the restistors and capacitors
determining the frequency).  The second periodic functions is the PC
in a loop polling the parallel port.
	The whole circuit can be built for $5-$10 worth of parts.  It
should also be possible to rig it up as a passthrough device, in case
you don't have an extra parallel port.

-- 
| Jeremy Porter  -----------------  Dell Computer Corp. ----
| Systems Engineering --- jerry@terminus.us.dell.com --------
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