What is multi-factor authentication (MFA)?

Multi-factor authentication (MFA) is a security mechanism designed to enhance access control by requiring users to provide two or more verification factors to gain access to a resource, such as a system or application. The primary principle behind MFA is that relying on a single factor, typically a password, is often not enough to secure accounts and data effectively. By requiring additional factors, such as something the user has (like a smartphone or hardware token), and something the user knows (like a PIN or password), MFA significantly reduces the risk of unauthorized access.

This approach leverages different categories of authentication methods: something you know, something you have, and something you are (biometric data). Combining these factors strengthens security, making it much more challenging for attackers who might compromise one of the factors, such as stealing a password.

The other choices do not accurately encapsulate the concept of MFA. For example, encryption pertains to data protection during transmission and does not involve multiple verification factors for user access. Single sign-on (SSO) technology allows users to log in once and gain access to multiple systems without re-authentication, but it doesn't inherently require multiple factors. Firewall configurations focus on network security and traffic control, which, while crucial, do not involve the multi-layer