Multi Factor Authentication (MFA)

MFA: a method of authentication that requires two or more kinds of evidence (something that the user “has” + “knows” + …)

But in reality, 2FA (Two Factor Authentication) means:

"Something that you forgot" + "Something that you lost" ;)

MFA:

Strong MFA: ** Adaptive MFA (AMFA)**: invisible process to interrogates various factors (password, biometrics, cognitive behavior, etc.) to provide additional level of protection that dynamically adapts security and authentication policies based on user and device content. It’s adaptive because if there is enough of a match with a user’s known profile, no need to provide any additional factors.

Reference:

How Attackers Bypass MFA <– example of aMFA

AMFA poster <– comparios of various MFA approaches