http://ciisqbg45nggykdl6rjdrq3wc64csga4vkphu66qsi65mypeitqedoad.onion/blog/pq-openvpn
Specifically, it's derived from CRYSTALS-Dilithium, and relies on the Module Learning With Errors (MLWE) problem. It offers strong resistance against both classical and quantum attacks, with an estimated 256-bit classical security level.