[realtarget]

You could use any kind of hardware token like RSA, Fortinet or many other manufactors. The usually offer a software version four your desktop as well. But usually you'll hate this additional piece of crap in your pocket. The combination of something in your mind (password) and something in your hand (smartphone) is the optimal setup. If you have a password or fingerprint to unlock your phone and the token generator app for 2FA it should be enough security.