Very cool, although I have some reservations about "... closest vector problem is believed to be NP-hard and even quantum-resistant". "Believed to be" is kind of different from "known to be".
all modern encryption is currently held together by asymmetric encryption that are all based on "believed to be" foundations not "known to be" foundations
If it makes you feel better, no cryptographic assumptions we use today are known to be NP-hard. Or maybe that makes you feel worse, not sure. But it doesn't really matter because NP-hardness is a statement about worst case inputs and cryptography needs guarantees about average case inputs since keys are generated randomly.