What is multi-factor authentication (MFA)?

Multi-factor authentication (MFA) is defined as a security process that requires two or more verification factors to gain access to a resource, such as an application, online account, or network. This method enhances security by combining different types of authentication methods that typically fall into three categories: something you know (like a password), something you have (such as a smartphone or security token), and something you are (based on biometrics like a fingerprint or facial recognition).

The use of multiple verification factors makes it significantly more challenging for unauthorized users to gain access, as they would need to have all the required factors, which provides an added layer of security compared to traditional single-factor authentication methods that rely solely on a password. This comprehensive approach is particularly important in today's digital landscape, where threats and cyberattacks are increasingly sophisticated.

The other options do not properly define MFA. For instance, unifying various access methods doesn’t capture the essence of using multiple verification factors. Similarly, requiring multiple passwords alone does not necessarily mean that other forms of verification are included, and while encryption plays a role in data security, it is not directly related to the concept of authentication processes.