Technical Guide

EMV contactless transactions, commonly known as "tap-to-pay" or "wave-and-pay," allow cardholders to complete card-present payments by holding a dual-interface chip card, wearable, or mobile device within ~4 cm of an NFC-enabled terminal. These transactions adhere to the same cryptographic...

(From official FIDO Alliance specs, W3C WebAuthn Level 3, and real implementations – December 2025) What is CTAP2? CTAP2 (Client to Authenticator Protocol 2) is the FIDO2 authenticator-side protocol that enables external security keys (YubiKey, Titan Key) and platform authenticators (built-in...

(From Apple Pay documentation, EMVCo, Visa/Mastercard token specs) What is DPAN? DPAN stands for Device Primary Account Number. It is the tokenized card number unique to a specific device (iPhone, Apple Watch, Mac) in Apple Pay. Key Facts: DPAN is not the real PAN (Primary Account Number on...