|“||associate a user with a particular identity. People are authenticated by three basic means: by something they know, something they have, or something they are. People and systems regularly use these means to identify people in everyday life.||”|
"For example, members of a community routinely recognize one another by how they look or how their voices sound — by something they are. Automated teller machines recognize customers because they present a bank card — something they have &mdash and they enter a personal identification number (PIN) — something they know. Using a key to enter a locked building is another example of using something you have. More secure systems may combine two of more of these approaches.
While the use of passwords is an example of authentication based on something users know, there are several technologies based on something users have. Security tokens can be used to authenticate a user. User information can be coded onto a token using magnetic media (for example, bank cards) or optical media (for example, compact disk-like media). Several smart token technologies containing an integrated circuit chip that can store and process data are also available. Biometric technologies automate the identification of people using one or more of their distinct physical or behavioral characteristics — authentication based on something that users are. The use of security tokens or biometrics requires the installation of the appropriate readers at network and computer access points.