You’re at the checkout screen after an online shopping spree, ready to enter your credit card number. You type it in and ...

All mainstream credit card numbers obey a mathematical trick designed to catch the most common typos. It’s called the Luhn ...

The Luhn algorithm—also known as the “Modulus 10 algorithm”—is a formula used to determine the accuracy of credit card numbers.

You can do that because credit card numbers aren’t random. Using terms that sound like something out of a spy novel — such as MIIs and the Luhn algorithm — you can decode parts of a credit ...

The Luhn Alogorithm The Luhn algorithm is based around the principle of modulo arithmetic and digital roots. The Luhn algorithm uses modulo-10 mathematics. To calculate the check digit, multiply ...