Provably Secure Post-Processing of a True Noise RNG? My customer wants an RNG that uses a true noise RNG and a post-processor that will provide provable security against recovery of the true noise RNG output.  

Is there a provably and post quantum secure hash function that I could use?
If your entropy extraction algorithm is well written and satisfies the relationship (entropy in) > (entropy out), there is no issue with recovery.  A lot of TRNGs do not even use cryptographic hash functions for extraction. A simple matrix multiplication acting as a compression function will do (as long as its compression window is wider than any length of auto correlation).

You can't recover the raw data if my above relationship holds true due to the pigeon hole principle, but even if you did it would be pointless.  That entropy has been used up and will never again be used. The TRNG will then create more entropy for the next set of random numbers. So as long as you're using a true random number generator with a good entropy extraction technique your concern is moot, quantum attack computer or otherwise.