With a single tap, your payment is approved in seconds. No swiping, no inserting your card, and no typing a PIN in many cases. But if your card sends information wirelessly, why can't someone simply capture that signal and use it again?

In this episode, we explore the incredible engineering and cryptography behind contactless payments. We dive into computer science, cybersecurity, electrical engineering, wireless communication, and financial technology to understand how tap-to-pay systems generate unique, one-time security codes for every transaction, making each payment different from the last.

We examine Near Field Communication (NFC), EMV chip technology, tokenization, dynamic cryptograms, encryption, secure elements, digital wallets, and the authentication systems that allow billions of secure transactions every day. We also explo ...