My question is essentially the same as this one.
The random oracle is a black box that does two things.
- Maintain a lookup table for any query that has already been asked.
- For all new queries, toss a bunch of coins to obtain a sufficiently long uniformly random bitstring.
As far as I can tell, 1. sounds straightforward. For 2., why not use randomness from a quantum measurement outcome to achieve the coin flip? What part of this black box fails as a valid instantiation of a random oracle?