By Michael Pruser 11 Comments Have you ever taken all of your credit cards, spread them out on a coffee table and noticed patterns in the 16 digit numbers?  Well, neither have I.
Hans Peter Luhn patented an algorithm in 1954 which would forever be known as the Luhn algorithm.
Using the credit card example below, let’s take a look at how the Luhn algorithm works. If we add up all of these single digits, and the total is divisible by 10 (without a remainder) we have ourselves a valid credit card number.  Unfortunately for all you fraudsters out there, the number we have adds up to 66, which is not divisible by 10, making the credit card above, a fake. Maybe if somebody had told Tom Hanks at the beginning of the Da Vinci Code about the Luhn algorithm, he might have had a much easier time unlocking the secrets of the Knights Templar.

I also remember reading a blog post somewhere that said the numbers also indicate the bank issuing the card, the type of card (Visa, MC, Amex, etc). Did you also know that depending on the length of the credit card number, the chances of keying in an incorrect number can be 1 in 100,000 or even 1 in a trillion? Advertiser Disclosure: This site may be compensated in exchange for featured placement of certain sponsored products and services, or your clicking on links posted on this website.
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