What should the 3rd factor be in 3FA?

Two factor authentication combines two of the three possible factors of authentication:
1. something you know (i.e. password);
2. something you have (i.e. key or token); or
3. something you are (i.e. fingerprint or retina scan)
3FA would use all three and probably be overkill in most cases.

Your mom has to approve the login from her cell phone

>>59098559
rectal temperature

Dick scan

>>59098559
>send us a copy of your state-issued ID t. facebook

National loyalty test

>>59098559

>ionize full body
>device sucks it up
>device verifies every single atom, quanta and strings
>device reconstructs your body

all of this happens already when you solve a captcha on 4chan .. its so fast you dont even notice : ^ )

IQ-test.