What Is the Luhn Algorithm? The Math Behind Credit Card Transactions
5 days ago
- #error detection
- #credit card validation
- #Luhn algorithm
- The Luhn algorithm is a mathematical trick used to detect common typos in credit card numbers.
- Credit card numbers have a specific structure including a major industry identifier, issuer identification, account number, and a check digit.
- The Luhn algorithm works by doubling every other digit starting from the right, summing the resulting digits, and checking if the total is a multiple of 10.
- The algorithm detects single-digit errors and most adjacent digit swaps, except for 09/90 transpositions.
- Dutch mathematician Jacobus Verhoeff developed a more comprehensive algorithm, but Luhn's remains widely used due to its simplicity.
- Luhn's algorithm saves time and money by catching errors before more resource-intensive validation services are needed.
- Passing the Luhn check doesn't guarantee a valid card number, but failing it guarantees an invalid one.