Re: Simple Hardware RNG Idea

At 4:14 PM 9/28/95, cjs wrote:
>Hello all.
>
>Someone mentioned this on IRC last night, and it sounded like a really
>cool idea, so I thought I'd mention it.
>
>The idea is to generate random numbers using a geiger counter tube and
>a small portion of radioactive substance (like perhaps the stuff they
>use in smoke detectors?) Would that be random enough?
>
>I thought it was a neat idea anyway.


It's a well-known idea. My FAQ has a section on this, and the Cypherpunks
archives have many mentions of this.

For the newcomers, here are some of the issues, very briefly presented:

1. Incorporating a "Geiger counter tube" is nontrivial. A solid-state
detector does the same thing, and is a better approach.

2. Incorporating Am-241 or other alpha emitters in microcurie levels would
require licensing, regulatory oversight, etc., etc. Don't count on it.

3. Data rates are fairly low. Anything that "clicks" at high rates (> 1K
counts per second) would be too radioactive to ship.

4. Zener diodes and other random noise sources are cheaper to build, more
consistent in output, and easier to integrate into actual products.

--Tim May

---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
Corralitos, CA              | knowledge, reputations, information markets,
Higher Power: 2^756839      | black markets, collapse of governments.
"National borders are just speed bumps on the information superhighway."

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howdy cpunks,

regarding the use of radioactive material for generating random
numbers, lantern mantles are fairly radioactive.  i'd say they would
be able to emit sufficient particles for OTP use, especially if one
builds a device that just constructs the pads all the time (ie, it
just sits there making various pads of X min length and Y max length,
storing them on a hard drive, or RAM if you're that rich).  you just
request a pad from the machine when you need it and encrypt whatever
with it... 

- -pjf
 
patrick finerty = zinc@zifi.genetics.utah.edu = pfinerty@nyx.cs.du.edu
U of Utah biochem grad student in the Bass lab - zinc fingers + dsRNA!
** FINGER zinc-pgp@zifi.genetics.utah.edu for pgp public key - CRYPTO!
zifi runs LINUX 1.2.11 -=-=-=WEB=-=-=->  http://zifi.genetics.utah.edu 


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Timothy C. May writes:
> 2. Incorporating Am-241 or other alpha emitters in microcurie levels would
> require licensing, regulatory oversight, etc., etc. Don't count on it.
> 
> 3. Data rates are fairly low. Anything that "clicks" at high rates (> 1K
> counts per second) would be too radioactive to ship.
> 
> 4. Zener diodes and other random noise sources are cheaper to build, more
> consistent in output, and easier to integrate into actual products.

However, radiation detection devices are far easier to assure correct
operation. You can buy pre-built radiation counters with RS-232
interfaces, so its really just a question in many cases of buying them
and small radation sources, the latter of which is available in most
scientific supply catalogs. Unlike other devices, its very hard for
outsiders to tamper with radation sources to make them produce
specially skewed numbers....

Perry