Microsoft® Windows® Security: Essentials

Comparing the Three Factors of Authentication

Authentication occurs when an entity presents credentials and the credentials are verified as valid. For example, when a user logs on with a username and password, the system checks to ensure that the username and password are valid and, if so, authenticates the user.

You’ve probably accessed systems using a username and password before, but there are other methods of authentication that may be configured in higher-security environments. The three primary types, or factors, of authentication are as follows:

Something You Know This includes information such as passwords or personal identification numbers (PINs).

Something You Have This includes items you can hold, such as a smart card.

Something You ...