Authentication can be performed to a system by another system and/or by a person using a system.
The process of authentication proves you (or the system) is who you are by your actions, such as a password with a username, who you say you are to that system. That you (or the system) are authentic, that is, genuinely you (or the system).
There are many methods for authentication and a combination of these methods is known as multi-factor authentication. Methods for authentication are categorised by their ‘type’. That is,
- something you know (eg. a password)
- something you have (eg. a swipe card)
- something you are (eg a fingerprint, face – as in facial recognition, or other biometric scan)
- something you do (eg. key strokes or gestures)
In Multi Factor Authentication more than one method from each of 2 or more of these categories or ‘types’ of authentication are used.