Credit Cards - Breaking the Code: The maths behind bank numbers and the Luhn test

TL;DR

Credit card numbers use a specific encryption algorithm to ensure security and validity, making it difficult to create fake credit cards.

Transcript

credit cards use a rather similar idea similar encryption but it's a little different and we're gradually working towards an understanding of what is the general structure of all these things so probably your credit card um it may have a 12 or a 16 digigit form here's a 16 digigit form so I've just invented uh a number here and uh what we do is tha... Read More

Key Insights

• 💳 Credit card numbers are encrypted using The Loon test algorithm, which has been an industry standard since the 1950s.
• 🥇 The encryption algorithm involves doubling odd-placed digits and creating a weighted sum with even-placed digits.
• 🔂 The algorithm catches single-digit mistakes, typing errors, and most adjacent number swaps.

Summary & Key Takeaways

• Credit card numbers typically have a 12 or 16-digit form.

• The encryption algorithm used for credit card numbers, known as The Loon test, was created by Peter Loon in the 1950s and remains an industry standard.

• The algorithm involves doubling odd-placed digits, handling results larger than nine, summing the digits, and ensuring the final number is divisible by ten for validity.