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Autor: Arnt Gulbrandsen
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Para: dng
Assunto: Re: [DNG] ID Quantique "Quantum" PCI-e RNG's - does anyone have more info?
Taiidan@??? writes:
> I can't imagine it being equivalent to a (non-intel/amd)
> hardware source of entropy when it comes to quality of entropy -
> have there been any quality analysis performed?


Yes. But it misses the point.

http://www.irisa.fr/caps/projects/hipsor/publications/havege-tomacs.pdf and
http://www.irisa.fr/caps/projects/hipsor/publications/havege-rr.pdf state
it clearly:

Havege is not a entropy gatherer like the Simtec device or the new Intel
CPUs, both of which rely on quantum physics. Neither is it a PRNG. Instead
it is a third class, namely an observer of unreproducible state changes.
Havege says: Modern computers can be measured more accurately than they can
be modelled, and the additional accuracy provides a stream of numbers that
are practically like entropy. They use the word "practically".

After reading the source and both papers, I accept that there is such a
stream. I just don't accept that the stream is as fast-flowing as they
think. Now, can you analyse the speed of the stream in a way that's really
different from what's in their source code (and mentioned in their papers)?
AFAICT you cannot. Their own analysis goes as far as reasonably possible.
What remains is the philoshophical point: Do you classify an observer of
unreproducible state as a PRNG or as like entropy?

> It is a shame IDQ is the only vendor with a PCI-e device, and
> also the only vendor it seems that offers something quality and
> obtainable (I can't find an open source hardware entropy device
> that is really for sale right away


And IDQ won't take you seriously?

Long ago I shared office with an extremely capable salesman for a while. He
was a bit of a cynic and very, very skilful. The company's top salesman in
terms of money. One of the things he told me was about prospective
customers who choose not to buy the product because it doesn't X. He said:
"Those never buy. If we X they just find a missing Y." The prospects worth
taking seriously were (according to him) are the ones who bought from a
competitor and said they'd switch if X. Their present outlay proved their
sincerity in his eyes.

Arnt