Common implementations of strong authentication may use which of the following factors in their
authentication efforts (choose all that apply):

A.
‘something you know’

B.
‘something you have’

C.
‘something you are’

D.
‘something you have done in the past on this same system’

E.
‘something you have installed on this same system’

F.
None of the choices.

Explanation:

Two-factor authentication (T-FA) refers to any authentication protocol that requires two
independent ways to establish identity and privileges. Common implementations of two-factor
authentication use ‘something you know’ as one of the two factors, and use either ‘something you
have’ or ‘something you are’ as the other factor. In fact, using more than one factor is also called
strong authentication. On the other hand, using just one factor is considered by some weak
authentication.