C validating a credit card

They follow whatever coding scheme that particular card company chooses.

The last digit, however, is generated by performing a fixed set of calculations on the other digits.

This code sample demonstrates the algorithm for validating a credit card number.

Almost all credit card companies use the same method for generating card numbers.

guys i have this assignment about luhns algorithm and i cant seem to know where to start (i am very weak in functions and arrays) , if anyone can help me out with the start of the i would be very thankful then later on i will be disscussing my doubts. Credit cards use a system of blocked numbers similar to the ISBN.

The first digit of a credit card number is the Major Industry Identifier (MII) and identifies which group issued the card. Including the MII, the Issue Identifier is 6 digits long.

The algorithm is in the public domain and is used to validate Canadian social insurance numbers.The Luhn algorithm or Luhn formula, also known as the "modulus 10" or "mod 10" algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers, IMEI numbers, National Provider Identifier numbers in the United States, Canadian Social Insurance Numbers, Israel ID Numbers and Greek Social Security Numbers (ΑΜΚΑ). 2,950,048, filed on January 6, 1954, and granted on August 23, 1960.It was created by IBM scientist Hans Peter Luhn and described in U. The algorithm is in the public domain and is in wide use today. It is not intended to be a cryptographically secure hash function; it was designed to protect against accidental errors, not malicious attacks.Most credit cards and many government identification numbers use the algorithm as a simple method of distinguishing valid numbers from mistyped or otherwise incorrect numbers.The sum of all the digits in the third row is 67 x.