The authentication factors of a multi-factor authentication scheme may include:
1. Something the user has: Any physical object in the possession of the user, such as a security token (USB stick), a bank card, a key, a phone that can be reached at a certain number, etc.
2. Something the user knows: Certain knowledge only known to the user, such as a password, PIN, PUK, etc.
3. Something the user is: Some physical characteristic of the user (biometrics), such as a fingerprint, eye iris, voice, typing speed, pattern in key press intervals, etc.
Email and phone are both in category one, comprising only one unique factor.
The authentication factors of a multi-factor authentication scheme may include: 1. Something the user has: Any physical object in the possession of the user, such as a security token (USB stick), a bank card, a key, a phone that can be reached at a certain number, etc. 2. Something the user knows: Certain knowledge only known to the user, such as a password, PIN, PUK, etc. 3. Something the user is: Some physical characteristic of the user (biometrics), such as a fingerprint, eye iris, voice, typing speed, pattern in key press intervals, etc.
Email and phone are both in category one, comprising only one unique factor.