Access Control Types
Type I: What you know – Access control methods related to “what you know” include passwords, numeric keys, PIN numbers, secret questions and answers, and so forth. Basically, Type I access control depends on the user knowing something in order to access the information.
Type II: What you have – You probably use this access control method every day without realizing it. A physical key is used to open a door to your house through a lock – a form of Type II access control. In information security terms, Type II access control methods may include physical keys or cards, smart cards, and other physical devices that might be used to gain access to something.
Type III: What you are – This form of access control is closely related to biometrics or authentication by biological factors. Some high-tech systems may use fingerprints, retinal scans, or even DNA to ensure that a user is who he claims to be. This type of access control is considered the most secure because it requires that a user be physically present whereas the other two can be compromised by theft of a password or a keycard.