What is two-factor authentication?

Two-factor authentication is defined as a security process that requires two different forms of identification from the user to grant access to an account or system. This method enhances security by adding an additional layer beyond just a username and password. Typically, one factor is something the user knows, such as a password, and the second factor is something the user has, like a mobile device to receive a verification code or a hardware token.

This approach significantly reduces the risk of unauthorized access, even if one of the authentication factors is compromised. For instance, even if a password were stolen, a potential intruder would also need the second factor to gain access.

The other options do not encapsulate the essence of two-factor authentication. A single identification method does not align with the principles of enhanced security. Similarly, a password combined with a security question does not fulfill the two-factor requirement since it still relies on something known rather than incorporating a second, distinct identification method. Finally, relying solely on biometric data, such as fingerprints or facial recognition, also does not meet the two-factor criteria as it only involves one form of identification.