The other systems are provably as secure on quantum computers as they are on classical computers. Quantum complexity classes are well mapped out, and it s known

The other systems are provably as secure on quantum computers as they are on classical computers. Quantum complexity classes are well mapped out, and it s known certain things cannot b one faster on quantum. Related to crypto, only systems reducible to DLP (well, technically Hidden Subgroup Problem but only for certain groups) are affected. This has the rigor of mathematical proof: it’s not handwaving. And many systems do not reduce to this.