What is multifactor authentication (MFA)?

Multifactor authentication (MFA) is an authentication method that requires two or more verification factors from different categories to confirm a user's identity. These factors can include something the user knows (like a password or PIN), something the user has (such as a smartphone or security token), or something the user is (biometric data like fingerprints or facial recognition).

By requiring multiple factors, MFA significantly enhances security. For instance, even if a malicious actor obtains a user's password, they would still need the additional verification factor (like a text message code) to gain access. This layered approach makes it much harder for unauthorized users to breach an account, thereby greatly reducing the risk of identity theft and unauthorized access.

The other options do not accurately reflect the concept of MFA. The first option refers to a single factor, which does not encompass the necessary components of MFA. The third option misrepresents MFA by limiting it to unique user IDs, failing to mention the multiple factors required. The fourth option incorrectly categorizes MFA as an encryption method, which is related to data protection rather than user authentication.