The two main concerns of ATMs are:
  • The ATM dispenses, requested functionality to a bona fide holder of a card which operates the ATM.
  • The ATM should prevent an unauthorized user of the card from gaining access to the machine’s functions.
NOTE : These two issues are taken care by Personal Identification Number (PIN).

ATM Switch

An ATM switch is basically an electronic device that routes traffic from Automated Teller Machine to the host processor of the Bank.