ATM System Peripherals (ASP)

ATM (Automatic Teller Machine) is one of the technologies that implements the concept of Digital-based Data Processing. This device has two important parts, namely Hardware consisting of a Processing Unit in this case a PC, as well as a device interface system that connects users through a magnetic card, and Software that functions as an interface that connects Users with the System in relation to Data (Information).

In general, ATMs can be hacked because ATMs still use the principles of most computer systems in interacting with users. How does an ATM work, what are its main parts (blocks)? What sensors or transducers are used in the ATM system and what is the interface system installed there?

ATM machines consist of several parts, namely:

Monitor
Customer keypad (to process data input from ATM buttons).
Card reader
Journal printer
Receipt Printer
Combination lock
Dispenser module Dispenses money
Cash cassette
Reject cassette
CPU

The working principle of an ATM is generally the same as a computer through data processing and processing, data is entered in the form of a card containing a code and the data is then processed by the machine through several data processing devices with instructions given by the customer. After the data has been processed, the results are in the form of money and a report on the data process and transactions carried out.

For sensors and transducers, in my opinion, they are both used. Basically, the ATM peripheral system (interface) is the same as a computer, not much different, only the usage capacity is different, that's my comment, maybe you can explain it further, thank you.

The working principle of an ATM machine

Magnetic strip is a short plastic form coated with a magnetic system and is usually attached to a credit card or other valuable card. On magnetic strips are usually written personal data of the cardholder, which contains the account number, personal number and access code. And this writing is written in the form of certain codes, and can only be read by a computer equipped with a special machine for the magnetic strip card.

The money machine used to read cards with plastic magnetic-strips is then known as an ATM (Automated Teller Machine). To use it, the user must insert the card they have into a special machine or ATM machine and enter the password number, and the amount of money to be withdrawn. This password number is then sent via the telephone network to the central computer. The computer will see whether the person concerned has money in savings or not.

If it has, then this signal is sent back to the ATM and then, the ATM will issue a certain amount of money according to the needs required. In addition, users can also see balance information from their savings, checking accounts or deposits. Automatic transfers will be done by the computer. At the ATM (Automated Teller Machine) there is also a satellite that will send the information to the central computer.

The ATM system consists of

A work station that can be accessed with a special card or also known as an ATM machine

Remote Computer that stores and updates customer records and authorizes and executes transactions

Telecommunications connection between ATM machine and remote computer.

For more complete information and pictures of ATM card readings, I will attach them via your e-mail. If my e-mail has been received, please reply back, sir. Thank you.

An ATM is a money machine that is used to read cards with plastic magnetic strips. To use it, the user must insert the card they have into a special machine or ATM machine and enter a password number, as well as the amount of money to be withdrawn. This password number is then sent via the telephone network to a central computer. The computer will see whether the person concerned has money in savings or not.

Some types of ATMs:

ATM (Cash Dispenser) Front Load / Front Door (Front Open)
ATM (Cash Dispenser) Rear Load / Rear Door (Rear Open)
ATM (Cash Dispenser with Depository), ATM with deposit facilities
and other types with optional equipment provided by the ATM Vendor

ATM Brand:

IBM Diebold
NCR
Siemens
Digital
etc…

ATM machines consist of 2 parts

a. Upper Compartment:

Monitor
Customer keypad
Card reader
Journal printer
Receipt Printer

b. Lower Compartment:

Combination lock
Dispenser module
Cash cassette
Reject cassette
CPU
Magnetic Card Reader

The use of ATMs by customers is possible with an ATM card. After the ATM card is inserted into the ATM machine, the card will be read by the magnetic card reader in the machine. The function of the magnetic card reader is only as a reader and receiver of data. After being read, the data is then sent to the bank's computerized system. Because its function is only as a data receiver, the magnetic card reader does not have a memory that can store customer data.

Scrambled Data

When the machine successfully reads the data on the ATM card, the machine will ask for the PIN (Personal Identification Number) data. This PIN is not on the ATM card but must be input by the customer. Then after the PIN is entered, the PIN data will be scrambled (encrypted) with a certain formula and sent to the relevant bank's computer system. The randomization of this PIN data is intended so that the data sent cannot be read by other parties.

ATM (Automatic teller machine or automated teller machine; in Indonesia it is also sometimes an abbreviation for anji teller mandiri) is an electronic device that allows bank customers to withdraw money and check their savings accounts without having to be served by a human "teller". Many ATMs also allow deposits of cash or checks, money transfers or even the purchase of stamps.

Magnetic Card Reader

Customers need to know that ATM machines do not store customer data or customer PINs. This is because the working principle of ATM machines is only to convey customer messages (pass through requests) to the bank's computer system.

Automatic teller machines (ATMs) are used by bank customers to conduct banking transactions. The main use of ATMs is to withdraw cash, check balances, pay mobile phone bills, buy train tickets, and so on. Transactions via ATM require a magnetic card (ATM) made of plastic and a PIN (Personal Information Number) associated with the card. The PIN consists of 4 digits that must be kept confidential by the ATM card owner, because other people who know can use a stolen or lost ATM card to withdraw money.

PIN is used to verify the card inserted by the customer in the ATM. The verification process is carried out on the bank's central computer (host), therefore there must be 2-way communication between the ATM and the host computer. The ATM sends the PIN and additional information on the card to the host computer, the host performs verification by comparing the PIN entered by the customer with the PIN stored in the host computer database, then sends a response message to the ATM stating whether the transaction can be continued or rejected.

Transactions via ATM require a magnetic card also called an ATM card. ATM (Automatic Teller Machine) works as an input-output device at the same time. As an input device, ATM allows users to enter PIN numbers, money figures, and other things available on the menu. As an output device, ATM allows users (bank officers) to see commands or codes and numbers typed on the input device.

ATMs are made of plastic and have a PIN (Personal Information Number) associated with the card. The PIN consists of 4 digits that must be kept confidential by the owner of a stolen or lost ATM card to withdraw money.

PIN is used to verify the card inserted by the customer in the ATM. The verification process is carried out on the bank's central computer (host), therefore there must be two-way communication between the ATM and the host computer, the host performs verification by comparing the PIN entered by the customer with the PIN stored in the host computer database, then sends a response message to the ATM stating whether the transaction can be accepted or rejected.

During the journey from the ATM to the host computer, the PIN must be protected from unauthorized eavesdropping. The form of protection carried out during transmission is by encrypting the PIN. On the bank side, the PIN stored in the database is also encrypted.

The encryption algorithm used is DES with ECB mode, because DES works by encrypting 64-bit blocks, then the PIN which only consists of 4 numbers (32-bit) must be added with padding bits so that its length is 64-bit. The padding bits added are different for each PIN, depending on the additional information on each ATM card [PIN02].

Since the PIN is only 4 digits long, the chance of being guessed is very high. Someone who obtains a stolen or lost ATM card can try all possible PIN codes, because there are 104 = 10,000 possible 4-digit PIN codes. To overcome this problem, most ATMs only allow a maximum of 3 PIN entries, if the 3rd attempt is still wrong, the ATM will 'swallow' the ATM card. This problem also shows that cryptography cannot always solve data security problems.

Some ATM networks now use smart cards, allowing the use of public key cryptography. The user's ATM card contains a private key and a digital certificate signed by the card issuer (CI) to certify the public key. The ATM authenticates the card by sending a string to the card to be handled using the private key, and the ATM then verifies the signature using the cardholder's public key.

Like all digital certificate-based systems, ATM terminals need to have a copy of the card issuer's public key in order to validate the digital certificate. This is realized by installing the public key into the ATM machine. For more details about this ATM card, I will attach it via email, if your email has been received, please reply, sir...

In ATM, all information to be transferred will be divided into fixed-size slots called cells. The cell size in ATM is 53 octets (1 octet = 8 bits) consisting of 8 octets for information fields, and 5 octets for hexacimal.

General Characteristics of ATMs

On a link-by-link basis, error protection and flow control are not used. In ATM, error protection can be ignored because it is currently based on very high quality link-by-link in the network, so it has a very small BER. And error control is sufficient to be done end to end only. Flow control is also not done in ATM networks because with the right resource allocation and queue dimensioning settings, the occurrence of queue overflow that causes packet loss can be suppressed. So that the probability of packet loss between 10-8 to 10-12 can be achieved.

ATM operates in connection oriented mode

Before information is transferred from the terminal to the network, a logical / virtual connection setup phase must be performed to provide the necessary resources. If the available resources are not sufficient, the connection from the terminal will be canceled. If the information transfer phase is complete, the resources that have been used will be freed again. Using this connection-oriented will allow the network to guarantee minimal packet loss.

Reduction of header function To ensure fast processing in the network, the ATM header only has a very limited function. The main function of the header is to identify the virtual connection (virtual connection identifier = VCI) selected during call setup and ensure proper routing for each packet in the network and allow multiplexing of different virtual connections through a single link. In addition to the VCI function, a number of other very limited functions are also performed by the header, especially related to maintenance functions. Because the header function is limited, the implementation of header processing in ATM nodes is very easy / simple and can be done at very high speeds (150 Mbps to 2.5 Gbps) and this will cause low processing delay and queuing delay.

Definition and Characteristics of ATM

ATM technology is one of the results of the Broadband Integrated Services Digital Networks (BISDN) standardization efforts carried out by ITU-T in the mid-1980s. ATM technology itself refers to a very high-speed data packet transmission technique using switching and time division multiplexing mechanisms applied to fixed-size and relatively small cells.

The main characteristics of ATM that differentiate it from other transmission techniques are as follows:

Information is transmitted in the form of fixed-size cells (53 bytes)
These cells are identified by labeling the header of each cell.
Cells are transmitted in a pre-arranged order.

Based on its capabilities, ATM has the following capabilities:

Supports services for all types of existing applications and future application developments
Provides very high utilization of network resources
Reducing complexity in switching
Reduces processing time on intermediate nodes and supports very high-speed transmission.
Reduces the size of the buffer required at intermediate nodes to avoid delays and buffer setup complexity.
Ensuring the performance required by current applications and their future developments.

ATM has a protocol that is based on the ISDN Protocol Reference Model (ISDN PRM) standardization []. This ATM protocol reference model consists of three layers as follows:

The physical layer (PHY) functions to define everything related to media use and bit transmission.
The ATM layer (ATM) serves to define the cell format and how to transmit these cells from one point to another.
The ATM adaptation layer (AAL) functions to map ATM services according to user needs.

Besides consisting of the three layers above, this reference model also consists of 3 planes, namely:

User Plane (U-Plane) which has the function of transmitting information from the user transparently.
The Control Plane (C-Plane) is responsible for sending information needed to control connections from the user plane (establishing/terminating a connection, monitoring the characteristics of a connection, etc.)

The Management Plane (M-Plane)

One of the developments in technology is the use of encoded lines on the back of a Bank card to carry information about a customer's account. Presented here is an intermediary for reading the lines.

The program controls the encoding of information on the lines and the movement of the card. The card is sensed by the rotary press, the actuator is turned on and the card is read. If it is not good or shows doubt, the card is discarded by the reader. If valid, the card is returned where each "1" bit is two transitions and each "0" bit is one transition, per bit cell. Thus, the data comes out of the reader head. If necessary, writing to the card can be read as it enters and written when it is returned. There must be a special software routine to reverse the data sensing so that the card can be read again when inserted.

The controls required are three inputs, card input sensing, serial data reading, card end sensing (reverse motor to return) and two outputs. Turn on the motor (it will automatically reverse, unless turned off) and the serial data to be written to half the 8255 PPI is sufficient for the input and output hardware.

Next, the hardware for reading and writing the card is checked. The electronics for writing will reverse the current passing through the write head, causing a change in the magnetic field on the card row. The reading section detects both positive and negative signals to ensure noise-free data retrieval.

ATM (Automated Teller Machine) is a money machine used to read cards with plastic magnetic-strips. ATM is useful for making a transaction that is usually done in a bank but we only do it with the help of a machine with the help of the card we have that has been accessed the cardholder's personal data, which contains the account number, personal number, and access code.

ATM machines work with the help of an online network with a computer working to make transactions using a card to enter the menu displayed on the ATM machine monitor. Without using a card, transactions cannot be made. When the machine successfully reads the data on the ATM card, the machine will ask for PIN (Personal Identification Number) data. This PIN is not on the ATM card but must be input. Then after the PIN is entered, the PIN data will be scrambled (encrypted) with a certain formula and sent to the relevant bank's computer system. The randomization of this PIN data is intended so that the data sent cannot be read by other parties.

The randomized PIN and the data from the card will be sent directly to the bank's computer system for verification. After the data has been processed in the bank's computer system, the data will be sent back to the ATM. Customers will get what they requested at the ATM. Please note that ATMs do not store data or PINs. This is because the working principle of ATMs is only to send messages (pass through requests) to the bank's computer system.