[117581] in Cypherpunks
re: otp
daemon@ATHENA.MIT.EDU (Anonymous)
Mon Sep 6 16:16:09 1999
Date: Mon, 6 Sep 1999 21:57:02 +0200 (CEST)
Message-Id: <199909061957.VAA26340@mail.replay.com>
From: Anonymous <nobody@replay.com>
To: cypherpunks@toad.com
Reply-To: Anonymous <nobody@replay.com>
At 10:24 AM 9/6/99 -0700, Tim May wrote:
>The dead time of the Geiger tube will stop this from working. Geiger
>counters are a poor choice for any such uses.
Yes. They're low b/w, with available isotopes.
And more fundamentally, *any* possible measurement will introduce biases
even if the raw source process is perfect.
This is exactly why you must *measure* the quality of
input, not just guess.
NB: If you want 'gold standard' randomness for calibrating
your measurement tools, use a block cipher feeding back on itself.
>Lots of better choices. Covered in past messages over the years.
Of course. But the original poster was clearly starting
to do some experimentation. Sharing experience is a
good thing. One expects the poster will come to agree
with your conclusions, but first hand experience is good.
Clearly, radioactive sources are for hobbyists only.
And although decay is "perfectly random" no measurement
can preserve this. One is better off with an audio source.
Or if one likes that kind of tinkering, build a circuit: check the patents
for this.
The quality-verification process is the same.
Audio is higher bandwidth. Hardware is much more
common. You can experiment with various sampling
resolutions.
You need audio volume: people
who record ambient noise, stereo-differences, etc.,
aren't getting the entropy-per-second they could by
e.g., placing the microphone near a spray nozzle on 'mist',
or (if you live in a dry climate) by using the
noise in a detuned radio, played loud.
And then, always, distill your data and measure until it doesn't get any
better with successive distillation. Because
there are *zillion* sources of bias and error in
a pc audio ADC, microphones or radio tuners, etc.
And hash before use.
[Hey Jeff Gordon: we're ANONYMOUSLY discussing RECIPES to COOK
MUNITIONS-quality random bits ON THE INTERNET. Pass it on to Diane and
Orrin at your next gangbang, eh?]
I have not found a serious study of detuned video receiver
entropy. Anyone?
BTW, I don't think the P-III lets you look at the
raw bits out of the RNG, does it? Some people like
to brew their own... and monitor the brewing process.
>This is not to imply support for OTPs or other such schemes.
>
>--Tim May
Odd comment. OTPs are perfect solutions for certain
types of problems/risk levels. They don't need anyone's
endorsement.
