With the installation of XF 1.5, two factor authentication is now possible with your account logins. For a detailed explaination on how it works, check out the first post in this thread: XF 1.5 - Two-Step Verification and Security Improvements | XenForo Community A word of caution. If you enable this and something goes wrong (you lose the phone, email gets hacked, etc.) I can't undo it as an Admin. Once you set it, only you can undo it.