Introduction on two factor authentication Please read the following information on two factor authentication and why you would want to use it. http://en.wikipedia.org/wiki/Two-step_verification NOTE: Make sure you leave a terminal with root access if you are using a remote system until you have tested that you can indeed authenticate to it! Steps tested on OpenBSD 5.4, used tools on EL6 client to generate QR code. I’m mainly documenting this here so I can remember how to do this again.