Memory Cards

A memory card is an authentication mechanism that holds user information
within a magnetic strip and relies on a reader of some sort to process the information. The user inserts the card into the reader and then enters a set of credentials
to be properly authenticated. An example of a memory card is an automated
teller machine (ATM) card. The user inserts the ATM card into the ATM machine
and then enters his or her PIN number. The card supplies the account number
(user information) and then the user provides the secret code (PIN), together
providing a credential set.
Within companies, employees will often carry ID badges with magnetic strips.
In many of these implementations, a PIN is hashed and stored on the magnetic
strip. In order to enter a building, the employee must enter a PIN number and
swipe the badge through a reader. The reader hashes the inputted PIN number
and compares it to the value on the card itself. If they match, access is granted.