From: tcmay@got.net (Timothy C. May)
Date: Sat, 30 Sep 95 12:44:49 PDT
To: cypherpunks@toad.com
Subject: Re: Simple Hardware RNG Idea
Message-ID: <ac92ed4110021004ff54@[205.199.118.202]>
MIME-Version: 1.0
Content-Type: text/plain


At 5:57 PM 9/30/95, zinc wrote:

>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...

Thorianated lantern mantles are only slightly radioactive. The counts per
second is what matters. This will be a function of a lot of things, not the
least of which is the detector area and the fluence of alphas intercepted.

At the risk of repeating myself, there are easier ways of generating
essentially random numbers.

--Tim May

(P.S., as my last word on this for a while. You may have heard that RAM
chips can have bits flipped by the alpha particles emitted by low levels of
uranium and thorium present in packaging materials. And that cosmic rays
can do the same thing, at a lower error rate. Well, I discovered these
effects in 1977 and wrote the original papers on this "soft error" effect.
I'm not making an appeal to authority here, just telling you why I'm
skeptical of all of these proposals to make a radioactive decay-based
random number source. There are much easier ways.)


---------:---------:---------:---------:---------:---------:---------:----
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.
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