Which of the following is NOT an example of two-factor authentication?

Two-factor authentication (2FA) enhances security by requiring two different forms of verification to grant access. These forms typically fall into three categories: something you know (like a password), something you have (such as a smart card), and something you are (like a fingerprint).

The scenario that involves a username and a password represents a single factor of authentication—both items are knowledge-based credentials. Even though a username and password together provide a level of security, they do not qualify as two distinct factors; they are both based on what the user knows.

In contrast, using a fingerprint and a pattern combines something you are (biometric) with something you know (the pattern), thereby meeting the criteria for two-factor authentication. Similarly, the combination of a password and a smart card utilizes a knowledge factor and a possession factor, while a password and a PIN number still fall under the same category of knowledge-based authentication, thus not providing the diversification required for two-factor authentication.

A comprehensive understanding of these distinctions is essential in recognizing effective security measures and implementing appropriate authentication methods in various scenarios.