dualauthentification

Dual authentication, also known as two-factor authentication (2FA) or multi-factor authentication (MFA) when more than two factors are used, is a security process that requires users to provide two different authentication factors to verify their identity. This layered approach significantly enhances security compared to single-factor authentication, which typically relies on just a password.

The core principle of dual authentication is to combine two distinct categories of credentials. These categories are commonly knowledge, possession, and inherence. Knowledge-based factors include things only the user knows, such as a password or a PIN. Possession-based factors are items the user possesses, like a smartphone that can receive a one-time code via SMS or an authenticator app, or a physical security key. Inherence factors are unique biological traits of the user, such as a fingerprint or facial recognition.

When a user attempts to log in, they first provide their primary authentication factor, usually their password. Once that is verified, they are prompted for a second factor from a different category. For instance, they might receive a code on their phone or be asked to scan their fingerprint. Only if both factors are successfully authenticated is access granted. This makes it much harder for unauthorized individuals to gain access, even if they manage to steal a user's password, as they would also need to obtain the second authentication factor. Dual authentication is widely implemented for online accounts, financial services, and sensitive corporate systems.