https://docs.nvidia.com/drive/drive_os_5.1.6.1L/nvvib_docs/i...
They've moved from keeping that sort of thing in EEPROM's to burnable fuses from what I understand, and I'm pretty sure what I'm aware of is pretty far behind state of the art.
If they've managed to set up the key management as well as they have and keep things hush-hushed enough to keep the nouveau folks obstructed, this seems either like an uncharacteristically careless mistake, or some seriously well executed malicious compliance from somebody.
Either way. I still find it irritating to the extreme that this type of thing only seems to happen to the detriment of users. Nvidia wins either way. Miners or gamers will buy out their cards.