Luhn algorithm

The Luhn algorithm is a simple checksum formula used to validate various identification numbers, like credit card numbers. It works by taking a number, doubling every second digit from the right, and then adding the digits of the resulting numbers together. If the total, including the untouched digits, is divisible by 10, the number is considered valid. This method helps catch common errors such as mistyped digits, enhancing accuracy and security in processes that rely on numeric identifiers.