Track content of the magnetic stripe of the card

[Tomcat]

The first track of the magnetic stripe contains the information embossed on the card (PAN card number, card expiration date, cardholder name), as well as the card service code (service code), country code (for some categories of card numbers) and issuer special data (Issuer Discretionary Data). There is a check character at the end of the track.

The service code consists of three digits X, Y, Z.

The first digit (X) identifies the geography (intercountry and / or intracountry transactions are allowed) and the technology (magnetic stripe card, microprocessor card) of using the card. The first digit of the code is 1 and 5, indicating that a magnetic stripe card is being used for intercountry and intracountry transactions, respectively. Values 2 and 6 indicate the use of the chip card for intercountry and intracountry operations, respectively.

The second digit (Y) defines the issuer's requirements for the method of authorizing transactions performed on the card. Specifically, it determines whether online transaction authorization is mandatory by the card issuer. The digit Y takes the following meanings:

Y = 0 - there are no restrictions on the method of authorizing the transaction, in part

ness, the transaction can be served offline;

Y = 2 - the transaction must be authorized by the issuer in the mode

real time;

Y = 4 - the transaction must be authorized by the issuer in the mode

real time, except for cases stipulated in special bilateral agreements between individual servicing banks and the issuer.

The rest of the second digit is ISO reserved. The second digit defines the rules for processing a transaction only when using magnetic stripe technology.

The third digit (Z) defines the list of services available with this card, as well as the method for verifying the cardholder. Possible Z values for various combinations of service / verification method are given below:

Z = 0 - any service and mandatory verification of the cardholder by PIN (No restrictions and PIN Required); example - Maestro cards;

Z = 1 - any service and any method of cardholder verification (No restrictions); the most common value of the third digit in practice;

Z = 2 - only purchase of goods and services and any method of cardholder verification (Good and Services only (no cash));

Z = 3 - only cash withdrawal through an ATM and mandatory verification of the cardholder by PIN (ATM only and PIN required);

MasterCard

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Z = 4 - cash withdrawal only and any method of cardholder verification (Cash Only);

Z = 5 - only purchase of goods and services and mandatory verification of the cardholder by PIN (Good and Services only (no cash) and PIN required);

Z = 6 - any service and verification of the cardholder by PIN code, when possible (No restrictions and require PIN when feasible);

Z = 7 - only purchase of goods and services and verification of the cardholder by PIN code, when possible (Good and Services only (no cash) and require PIN when feasible).

The rest of the Z values are reserved by ISO. The third digit defines the rules for processing a transaction only when using a magnetic stripe (the chip card uses Application Interchange Profile, Application Usage Control, CVM List, Issuer Action Code, etc. data objects, which will be discussed in Chapter 3).

101 is the most common service code value for magnetic credit cards, 121 for Maestro magnetic cards.

Special data of the issuer, stored on the magnetic stripe of the card, determine:

• data used to protect card transactions (these include the CVC / CW values to ensure the integrity of the magnetic stripe data elements of the card, the PIN Offset value, sometimes used when calculating the cardholder PIN code using the IBM 3624 algorithm, or the VISA PW value when the issuer uses the same-name algorithm for generating / verifying the cardholder PIN-code);
• PAN sequence number - a number that allows you to attach several different cards to one PAN account;
• operational characteristics of the card used by the issuer when authorizing card transactions, for example, the date after which the card is no longer valid (expiration date).

The second track contains the same data as the first, except for the name of the cardholder. In the case of using a credit card, the name of the cardholder must be printed on the check of the POS terminal. Therefore, for credit products, either the first track or the first and second tracks of the magnetic stripe are personalized (to increase the reliability of reading information from the magnetic stripe), while for debit cards, as a rule, only the second, shorter track is personalized.

The third track of the magnetic stripe contains:

• PAN card number, country code (for some categories of card numbers), card validity period, card serial number;
• geographical use of the map (international map, intra-country map);
• type of account (current, savings, credit).

On the third track of the card, you can write two additional account numbers. If during the operation it turns out that there are not enough funds on the main account of the cardholder, the issuer checks the availability of the necessary funds on the additional accounts of the card.

Unlike the first and second tracks, data can be written to the third track during the execution of a transaction. This provides additional opportunities for controlling card expenses and ensuring the security of transactions.

For example, you can set the amount of funds that can be spent within a specified time interval and control their spending in the process of using the card. As a result, parameters such as the end date of the current time cycle, the value of the amount of money available to the cardholder until the end of the current cycle, the value ensuring the integrity of the data of the third track, and the signature of the track data changed during the operation can be recorded on the third track.

Finally, with the help of the third track, you can control the number of remaining attempts to enter the correct PIN-code, store the date of the last operation on the card. It should be noted that changing the parameters of the third track of the magnetic stripe by the card issuer is possible only in the association of banks that support additional fields in the interbank interface. For example, such changes cannot be made using standard interfaces of international payment systems.

The third track has not become widespread, and almost all modern POS terminals do not use it for data recording.