[Cryptography] The ultimate random source

Bill Frantz frantz at pwpconsult.com
Thu Feb 20 20:09:53 EST 2014

On 2/18/14 at 1:05 PM, jon at callas.org (Jon Callas) wrote:

>On Feb 7, 2014, at 8:14 AM, Phillip Hallam-Baker <hallam at gmail.com> wrote:
>>I have a solution to the random number generator problem that can be built for about $50 and is
>completely verifiable.
>It works just as well, perhaps better, if you put a lens cap on 
>the camera. The ritual with the smarties just makes you feel better.

I feel better with a real image that can test that the camera is 
still working.

I did some experiments with the large bag of M&Ms in our pantry. 
I poured them into a 10" x 15" baking sheet and counted the 
number of M&Ms by weight and came up with slightly more than 600 
M&Ms.* (Note that the sheet wasn't absolutely densely packed 
because it was easier to not have a M&M sitting on top of 
another M&M that way.)

There were 6 different colors of M&Ms in the package.

Now my statistics is a bit rusty, and I know we can't assume 
equal color probability for each position, but I think we have 
so much margin here that a simplifying assumption is justified. 
We get 6 ** 600 possibilities and we haven't even considered 
small changes in position of each M&M. 6**600 overflows my HP15 
calculator and makes me feel comfortable seeding a PRNG.

Now the issue is to keep the photo secret. :-)

Cheers - Bill

* 50 M&Ms weigh 1.5 ounces on my digital scale with a resolution 
of 1/8 ounce. The total collection of M&Ms weighed 18.375 ounces.

Bill Frantz        | I don't have high-speed      | Periwinkle
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