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#### glen herrmannsfeldt

James Kuyper said:On 06/05/2014 06:54 PM, Stefan Ram wrote:

If that's what they measured, then I'm far less surprised by that result

than I was by your original statement of it. I'm so unsurprised, that

the fact that they consider it unexplained confuses me. Possibly I'm

missing something that makes that result less obvious than it seems to be.

Quantum randomness is always necessarily derived ultimately from

measurements of a quantum process. It's extremely difficult to ensure an

exactly even distribution when measuring something, even if the thing

you're trying to measure does, in fact, have an exactly uniform

distribution. Even the tiniest contamination of your measurement will

introduce some uneveness. It's far easier to ensure an absolutely even

distribution when generating pseudo-random numbers.

Yes. I had thought for that reason that they were using very low

bit rates, such as 1bit/s (slow enough that you can generate one

photon at a time, and be sure it is gone before the next one).

According to:

https://en.wikipedia.org/wiki/Quantum_key_distribution#Experimental

they now have some up to 1Mbit/s.

I doubt that it would be difficult to pick an arbitrary possible value

for the Borel normality test, and design a deliberately defective

pseudo-random number generator that would, on average, produce

that value.

As noted before, one way to remove bias from a hardware random

bit generator is to XOR with a cryptographically secure PRNG.

I suppose one could also use two different secure PRNGs and

XOR them together.

-- glen