A Smart Card is a plastic card the size of a credit card with an integrated circuit built into it. This integrated circuit may consist only of EEPROM in the case of a memory card, or it may also contain ROM, RAM and even a CPU. Most smart cards have been designed with the look and feel of a credit or debit card, but can function on at least three levels (credit – debit – personal information). Smart cards include a microchip as the central processing unit, random access memory Read More

Credit cards use the Luhn Check Digit Algorithm. The main purpose of the Luhn Check Digit Algorithm is to catch data entry errors, but it does double duty here as a weak security tool. The Luhn Check Digit Algorithm For a card with an even number of digits, double every odd numbered digit (1st digit, 3rd digit, 5th digit, etc…) and subtract 9 if the product is greater than 9. Add up all the even digits (2nd digit, 4th digit, 6th digit, etc…) as well as the doubled-odd digits, and Read More