With PAM, it's possible to configure any combination of authentication requirements, in any desired order, with optional steps etc.
One can require password AND keys AND physical token, in that order, or password AND keys OR physical token, or any other combination they desire.
With PAM, one could go as far as to write a module requiring them to whistle the scooby doo tune to unlock.
[0]https://en.wikipedia.org/wiki/Linux_PAM
With PAM, it's possible to configure any combination of authentication requirements, in any desired order, with optional steps etc.
One can require password AND keys AND physical token, in that order, or password AND keys OR physical token, or any other combination they desire.
With PAM, one could go as far as to write a module requiring them to whistle the scooby doo tune to unlock.
[0]https://en.wikipedia.org/wiki/Linux_PAM