Multi-Factor Authentication (MFA):. a. When identity is proven by presenting more than one item for proof of credentials -- e. g., something you know (user ID, password), and something you have (e. g., a tap of swipe of a card).
b. Devices themselves lack unique identifiers so they are not useful for multi-factor authentication (MFA).
c. Technology that identifies users via unique characteristics in speech.
d. Technologies that measure and analyze human body characteristics for identification or authentication.