A black box RNG is still useless despite being based on a quantum mechanism, or
That a quantum device will necessarily manufacture random bits.
Counterexamples to 2 are pretty straightforward (quantum computers), so I’m assuming you mean 1. I’m operating at the edge of my knowledge here (as my original mistake shows), but I think the entire point of Pironio et al’s paper was that you can verify random bits obtained from an adversary, subject to the conditions:
Bell inequality violations are observable (i.e., it’s a quantum generator).
The adversary can’t predict your measurement strategy.
Does putting the ‘quantum’ in a black box change anything?
Not sure I know which question you’re asking:
A black box RNG is still useless despite being based on a quantum mechanism, or
That a quantum device will necessarily manufacture random bits.
Counterexamples to 2 are pretty straightforward (quantum computers), so I’m assuming you mean 1. I’m operating at the edge of my knowledge here (as my original mistake shows), but I think the entire point of Pironio et al’s paper was that you can verify random bits obtained from an adversary, subject to the conditions:
Bell inequality violations are observable (i.e., it’s a quantum generator).
The adversary can’t predict your measurement strategy.
Am I misunderstanding something?