rich1.0jo (npub1pk…nxwks)https://nostr.ae/npub1pkx92m60skq9pzs90m3yqq9tvwh03xhzc0haeqqc4exjcu7l6ntsanxwksnjumphttps://nostr.aeproperties: . retroactive modification invalidates all subsequent hash states . multiple FELs may exist across institutions . verification is possible without revealing sensitive details