Factors of authentication
There are three authentication factors that can be used for granting access:
- Something you know: For example, a password, PIN, or some other personal information
- Something you have: For example, a token, one-time password, or smart card
- Something you are: For example, biometric features, such as a fingerprint, iris scan, or voice recognition
Similarly, two-factor authentication means the use of two authentication methods from the preceding list. For critical systems, it is advisable to use more than one factor of authentication for granting access. The following illustration indicates the implementation of two-factor authentication in a lighthearted way:
Figure 7.2 – Two-factor authentication
From the user's perspective, two-factor authentication will require additional effort, and therefore the security manager should strike a balance between ease of access and control.
