Automated Teller Machine
Automated Teller Machines (ATMs) are considered as the most influential technological innovation of 21st century. An Automated Teller Machine is a Telecommunication Device installed in the public so that people have access to their money without going to the Bank. The customer is identified by entering a Plastic Card with a Magnetic Strip or Chip in the ATM. All the information regarding the customer are available in the card. The customer needs to enter some PIN (Personal Identification Number) to perform the Transactions.
ATM is a data terminal which connects to the Bank Computer Network to retrieve the information through the Host Computer. The ATMs are connected to the Bank Computer Network using Internet or Telephone Lines.
There are provisions to count the notes and measure the thickness of the bundle of notes to ensure the correctness of the number of notes dispensed to the Customer.
There are three input devices in an ATM. They are Card Reader, a Key Pad and a Web Camera. The Card reader is used to get the information encoded in the magnetic strip of the ATM Card. Keypad allows us to enter the PIN number and other inputs to process or cancel a transaction. The pictures and videos captured in the Web Camera are used for security purpose. Most of the time, these videos will be recorded using a Digital Video Recorder.
The output devices in an ATM are: Speaker, LCD/CRT Screen, Receipt Printer and Cash Dispenser.
Most of the Modern ATMs contains a Secure Crypto Processor along with the CPU for the secure transmission and reception of the data from and into the ATM. Encrypting PIN Pad is used to secure the PIN numbers entered by the Customer. The encryption algorithm used for this purpose is DES 3 (Data Encryption Standard 3)
The Operating System used in the ATMs are mostly Microsoft Windows XP, 7, 8 or Linux variants.
Time Out: It is a security feature enabled in ATMs to enter the PIN number within a stipulated time. If the customer fails to enter the PIN within this time, the transaction will be cancelled.
Invalid PIN: This is another security feature enabled in ATMs to prevent unauthorized usage of ATM cards. If a person fails to enter the correct PIN within 3 attempts, the card will be disabled for next 24 hours.
In some countries the Modern ATMs has most advanced security systems like biometric, facial, retinal identification systems to avoid unauthorized access to Bank accounts.
How an ATM Works?
In order to access various accounts, ATM computers are connected to complex interbank networks, which allow customers from many different banks to access their accounts through the machine.
When an ATM transaction is processed, the machine starts communication with the network of the banks to begin the authorization process. The ATM machine has a unique TID (terminal ID number). This is how the networks allow the transaction to be completed. This TID along with other identifying information lets the cardholder’s bank know that the transaction is taking place on that particular ATM.
Now the ATM can connect to the networks through a processing center and then to the cardholder’s bank. If there are sufficient funds in the ATM cardholders account for the withdrawal request, the transaction will be completed. Once transactions are approved the ATM receives the authorization and dispenses the cash requested. Based on the cash dispensed by the ATM, an equal amount is deposited to the Bank which hosts the ATM and from there to the ATM. The ATM can also be used if someone just wants to check their account balance or transfer funds before or after withdrawing cash.