in the context of security in general, and cybersecurity in particular, authentication
is the act of confirming of the truth of an attribute of a single piece of data (a datum) claimed true by an entity.
There are several levels of security authentication:
- Single-Factor Authentication (SFA), where you need to provide at least one kind of credential, typically something that you know (see below), to authenticate;
- Two-Factor Authentication (2FA), where you need to provide two out of three kinds of credentials to authenticate.
- Three-Factor Authentication (3FA), where you need to provide three out of three kinds of credentials to authenticate.
The three kinds of credentials used to authenticate are listed below:
- Something that you know, such as a password, a Personal Identification Number (PIN), or a geometric pattern.
- Something that you have, such as an ATM card, credit card, mobile phone, or fob.
- Something that you are, such as a biometric id (e.g., fingerprint, voiceprint, iris scan).