Pronunciation: [lˈuːn] (IPA) 
"Luhn" (lün) is a word with a unique spelling that differs from standard English phonetics. The IPA transcription reveals that the "h" in "Luhn" is silent, and the letter "u" produces a sound similar to the German ü. This word is not commonly used in English; it is a surname derived from Germanic roots. The spelling of this word showcases the importance of understanding phonetics when encountering unusual or foreign terms.
Luhn, also known as the Luhn algorithm or the modulus 10 algorithm, is a mathematical formula used to validate the accuracy of a variety of identification numbers, primarily those that are found on credit cards and account numbers. It was developed by a computer scientist named Hans Peter Luhn in the 1950s.
The Luhn algorithm works by calculating a check digit, which is a single digit added to the end of a numerical string. This check digit is generated based on the preceding digits and serves as a verification tool to detect any errors in the number itself or prevent accidental mistypes or alterations.
To apply the Luhn algorithm, the numerical string is processed from right to left. Each digit is multiplied by 2, and if the resulting number is greater than 9, the digits of that number are summed. The sum of all the resulting digits is then added to the sum of the non-multiplied digits. The final check digit is the amount needed to reach the next multiple of ten.
The Luhn algorithm is widely utilized by financial institutions, e-commerce platforms, and other industries that require accurate identification number verification. It helps detect common errors like transpositions, accidental omissions, and other input mistakes. By utilizing this algorithm, organizations can validate the correctness of identification numbers, thus reducing the likelihood of errors in their systems.
