Thanks for the article! > QC can only solve two problems more efficiently than classical (and this is proven very thoroughly) I didn't see a discussion of the

Thanks for the article! > QC can only solve two problems more efficiently than classical (and this is proven very thoroughly) I didn't see a discussion of the proof in your article, although maybe I missed it. I thought your article instead emphasized that all quantum algorithms that have been discovered so far can only be more efficient relative to classical algorithms with problems that can be reduced to hidden subgroup problems. Is there some other research (that maybe you mentioned) that goes on to prove that no new quantum algorithm could ever do any better on other problems? If not, isn't this a conjecture (perhaps a widely-believed conjecture) of complexity theory? When I last looked at the Complexity Zoo, I thought there were quite a few different complexity classes that had been defined relative to quantum computing, and it was apparently unresolved whether many of them could be reduced to one another. I don't really know this area at all, beyond having heard of Grover's and Shor's algorithms and read the SMBC on what quantum computing doesn't do. And having seen some candidate PQ cryptographic algorithms, without understanding exactly why any of them were considered credible as candidates. :-)