Comment # 103 on bug 1173158 from Takashi Iwai

(In reply to Reinhold Patzer from comment #102)
> My problem is: the directory /var/lib/nvidia-pubkeys doesn't exist on my
> system.
> I deleted the Nvidia drivers and installed them again, but the directory
> still
> isn't there.

Did you enable the secure boot already at *installing* the Nvidia package?

The recent support of secure boot in Nvidia package is enabled only if the
system is already in secure boot mode at installing the package and running its
post-install script.  Then the one-time cert above will be generated.

So, try to re-install the Nvidia package while you already enable secure boot
on BIOS.