On "randomness"

[Peter Gutmann]

John Denker <jsd at av8n.com> writes:

>  *) At the other extreme, there are many high-stakes business,
>   military, and gambling applications where I would agree with 
>   von Neumann, and would shun absolutely all PRNGs.  I would 
>   rely exclusively on _hardware_ randomness generators, as
>   detailed at:
>      http://www.av8n.com/turbid/

I would never rely *exclusively* on any source because then a failure in your 
exclusive source, no matter how magical it is, will bring down your entire 
system.  Use a hardware RNG if you want to, but also XOR in the output from a 
PRNG, and a block cipher in counter mode, and a MAC of the time.  And apply 
the NIST tests on the data you're using, and on the generator output.  And 
don't forget to do [...].

A good randomness/key generator is more an engineering problem than an 
algorithmic one.

Peter.

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