Chapter 25 - Credit Card Numbers

Abstract

This chapter focuses on the various standards used for credit card numbers. Most credit card numbers have 16 digits, grouped in blocks of four digits, where the first digit is the Major Industry Identifier (MII), representing the category of the issuer of the card. The first six digits are complete issuer identifier, which limits the number of possible issuers to 1 million. The rest of the digits signify the account number with the final digit signifying a Luhn check digit. The Card Security Code (CSC), also known as Card Verification Value (CVV or CV2), Card Verification Value Code (CVVC), Card Verification Code (CVC), or Card Code Verification (CCV) is a three-digit number printed on the back of the card. American Express is the only exception, which puts a four-digit code on the front of its cards and calls it as CID or Unique Card Code. The Personal Identification Number (PIN) is created by the cardholder, which is never stored on the card itself. It is used to verify the user's identity at ATMs and other computer systems that can access the account at the issuer. The Payment Card Industry Data Security Standard (PCI DSS) is an international security standard defined by the Payment Card Industry Security Standards Council (PCI SSC). Their goal is to prevent credit card fraud, hacking, and other security vulnerabilities and threats and they issue guidelines and certification for software that handles payment card numbers.