Getting Started with Security Keys

I've recently moved to using a yubikey for u2f and I'm really impressed! Usually when you try to be more secure you lose some convenience, but in the case of u2f I've gained both security and convenience.

I've also tweaked some pam (a Unix auth stack) module settings so that I can required u2f in first login; and unlock the screen & run sudo with just my yubikey.

Since I shutdown my machine once a day and I am very disciplined to always have my keys in my pocket, I think I have a generally more secure system that is also more convenient to use.