Understanding the Luhn Algorithm: A Simple Verification Technique for Credit Cards

[codenerd]

The Luhn algorithm, developed by Hans Peter Luhn in the 1950s, provides a reliable method for verifying the validity of credit card numbers. In this post, we will delve into how the Luhn algorithm specifically works for credit cards and provide a clear example to illustrate its application.

The Luhn Algorithm Explained: The Luhn algorithm is a checksum formula used to validate credit card numbers. It follows these steps:

1. Starting from the rightmost digit and moving left, double the value of every second digit. If the result of the doubling operation is greater than 9, subtract 9 from the result.
2. Sum up all the resulting digits, including the digits that were not doubled.
3. If the total sum is divisible by 10, the credit card number is considered valid according to the Luhn algorithm. Otherwise, it is deemed invalid.

Example: Let's consider the credit card number 4532 7200 1234 5678 to demonstrate the Luhn algorithm for credit cards:

Step 1: Starting from the rightmost digit and moving left, we double every second digit. The resulting sequence becomes: 4 5 6 4 1 0 2 0 2 2 6 4 1 0 1 4.

Step 2: We sum up all the resulting digits: 4 + 5 + 6 + 4 + 1 + 0 + 2 + 0 + 2 + 2 + 6 + 4 + 1 + 0 + 1 + 4 = 48.

Step 3: Since the total sum (48) is divisible by 10, the credit card number 4532 7200 1234 5678 is considered valid according to the Luhn algorithm.

Usage and Benefits for Credit Cards: The Luhn algorithm is specifically utilized in the credit card industry for multiple purposes:

1. Detection of transcription errors: The algorithm can quickly identify common mistakes, such as transposed digits or mistyped numbers, that may occur during manual data entry.
2. Basic validation: While the Luhn algorithm does not verify the accuracy of the actual credit card data or account, it serves as an initial check to ensure the integrity of the entered credit card number.
3. Fraud prevention: By applying the Luhn algorithm, credit card issuers and payment processors can reduce the risk of processing transactions with invalid or counterfeit credit card numbers.

 

[Rkr]

The Luhn algorithm, developed by Hans Peter Luhn in the 1950s, provides a reliable method for verifying the validity of credit card numbers. In this post, we will delve into how the Luhn algorithm specifically works for credit cards and provide a clear example to illustrate its application.

The Luhn Algorithm Explained: The Luhn algorithm is a checksum formula used to validate credit card numbers. It follows these steps:

1. Starting from the rightmost digit and moving left, double the value of every second digit. If the result of the doubling operation is greater than 9, subtract 9 from the result.
2. Sum up all the resulting digits, including the digits that were not doubled.
3. If the total sum is divisible by 10, the credit card number is considered valid according to the Luhn algorithm. Otherwise, it is deemed invalid.

Example: Let's consider the credit card number 4532 7200 1234 5678 to demonstrate the Luhn algorithm for credit cards:

Step 1: Starting from the rightmost digit and moving left, we double every second digit. The resulting sequence becomes: 4 5 6 4 1 0 2 0 2 2 6 4 1 0 1 4.

Step 2: We sum up all the resulting digits: 4 + 5 + 6 + 4 + 1 + 0 + 2 + 0 + 2 + 2 + 6 + 4 + 1 + 0 + 1 + 4 = 48.

Step 3: Since the total sum (48) is divisible by 10, the credit card number 4532 7200 1234 5678 is considered valid according to the Luhn algorithm.

Usage and Benefits for Credit Cards: The Luhn algorithm is specifically utilized in the credit card industry for multiple purposes:

1. Detection of transcription errors: The algorithm can quickly identify common mistakes, such as transposed digits or mistyped numbers, that may occur during manual data entry.
2. Basic validation: While the Luhn algorithm does not verify the accuracy of the actual credit card data or account, it serves as an initial check to ensure the integrity of the entered credit card number.
3. Fraud prevention: By applying the Luhn algorithm, credit card issuers and payment processors can reduce the risk of processing transactions with invalid or counterfeit credit card numbers.

Wah kya baat hai....😀😀😀😀🫡🫡

 

[Venkatm]

Quite Informative

 

[AlphaCAT]

The Luhn algorithm, developed by Hans Peter Luhn in the 1950s, provides a reliable method for verifying the validity of credit card numbers. In this post, we will delve into how the Luhn algorithm specifically works for credit cards and provide a clear example to illustrate its application.

The Luhn Algorithm Explained: The Luhn algorithm is a checksum formula used to validate credit card numbers. It follows these steps:

1. Starting from the rightmost digit and moving left, double the value of every second digit. If the result of the doubling operation is greater than 9, subtract 9 from the result.
2. Sum up all the resulting digits, including the digits that were not doubled.
3. If the total sum is divisible by 10, the credit card number is considered valid according to the Luhn algorithm. Otherwise, it is deemed invalid.

Example: Let's consider the credit card number 4532 7200 1234 5678 to demonstrate the Luhn algorithm for credit cards:

Step 1: Starting from the rightmost digit and moving left, we double every second digit. The resulting sequence becomes: 4 5 6 4 1 0 2 0 2 2 6 4 1 0 1 4.

Step 2: We sum up all the resulting digits: 4 + 5 + 6 + 4 + 1 + 0 + 2 + 0 + 2 + 2 + 6 + 4 + 1 + 0 + 1 + 4 = 48.

Step 3: Since the total sum (48) is divisible by 10, the credit card number 4532 7200 1234 5678 is considered valid according to the Luhn algorithm.

Usage and Benefits for Credit Cards: The Luhn algorithm is specifically utilized in the credit card industry for multiple purposes:

1. Detection of transcription errors: The algorithm can quickly identify common mistakes, such as transposed digits or mistyped numbers, that may occur during manual data entry.
2. Basic validation: While the Luhn algorithm does not verify the accuracy of the actual credit card data or account, it serves as an initial check to ensure the integrity of the entered credit card number.
3. Fraud prevention: By applying the Luhn algorithm, credit card issuers and payment processors can reduce the risk of processing transactions with invalid or counterfeit credit card numbers.

Sum should be 42 , even if it’s 48 ; how is that divisible by 10 !?