Luhnalgoritmussal

Luhnalgoritmussal, often referred to as the Luhn algorithm or the "modulus 10" algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers and IMEI numbers. Developed by Hans Peter Luhn at IBM, it was patented in 1960. The primary purpose of the Luhn algorithm is to detect most single-digit errors and some transpositions of adjacent digits.

The algorithm works by performing a series of arithmetic operations on the digits of the number. Starting from the rightmost digit (the check digit) and moving left, every second digit is doubled. If doubling a digit results in a two-digit number, the two digits are added together (e.g., 7 doubled is 14, so 1 + 4 = 5). All the digits (the modified doubled digits and the untouched digits) are then summed up. If the total sum is a multiple of 10 (i.e., ends in 0), the number is considered valid according to the Luhn algorithm.

The Luhn algorithm is not a cryptographic hash function and provides no security against intentional fraud. Its strength lies in its simplicity and effectiveness at catching common input errors. It is widely implemented in systems that handle identification numbers to ensure data integrity during input and transmission.

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