What is multi-factor authentication (MFA)?

Multi-factor authentication (MFA) is defined as a security mechanism that requires two or more verification factors to gain access to a system or application. This approach enhances security by combining different types of authentication factors, which typically fall into three categories: something you know (like a password), something you have (like a smartphone or security token), and something you are (like a fingerprint or other biometric data).

By requiring multiple forms of verification, MFA significantly reduces the risk of unauthorized access. For example, even if a malicious actor obtains a user's password, they would still need the second factor, such as a code sent to the user's mobile device, to successfully log in. This layered security involves multiple checkpoints, making it much more challenging for attackers to compromise a system.

Considering the other options, relying on just a password does not offer sufficient protection, as passwords can be stolen or guessed. An encryption technique pertains to securing data rather than authenticating users. A single-step login process prioritizes convenience but compromises security by not requiring additional verification. Therefore, the essence of MFA lies in its ability to provide a more robust defensive strategy against unauthorized access through the use of multiple verification methods.