> There are a few hopeful candidates for quantum-secure classical asymmetric key systems, but there are no strong proofs that they are secure against either cla

> There are a few hopeful candidates for quantum-secure classical asymmetric key systems, but there are no strong proofs that they are secure against either classical or quantum systems. While technically correct, this is totally misleading. There are no cryptosystems at all that have strong proofs of security. (Minus one time pads, which are completely impractical.) Your QKD system also depends on a bunch of assumptions that you can't prove.