Put Tokenized wallet payment back in order

THE DRILL AS TEXT

1. In Tokenized wallet payment, what happens first, and what follows?
   • The card was already tokenised onto the device — Before any purchase, the wallet asked a token requestor to swap Maya's real card number (the PAN) for a device token (a DPAN) tied to this phone. The DPAN lives on the device; the real PAN never does.
   • Maya taps her phone to pay — Maya authorises on the device with a fingerprint or face check — the on-device strong customer authentication — and the wallet presents the DPAN plus a one-time cryptogram for this EUR 42.50 order, never the real card number.
   • The terminal sends an authorisation request on the token — Demo Coffee's terminal packs the DPAN, cryptogram, amount and merchant details into an authorisation request and sends it to Meridian Bank, its acquirer. The merchant only ever handles the token, not Maya's PAN.
   • Meridian Bank routes the request to Cardnet — The acquirer forwards the tokenised authorisation request into the card network so it can be detokenised and routed on to the right issuer.
   • Cardnet checks the token domain and detokenises — The network verifies the cryptogram and confirms the DPAN is being used within its allowed domain — this device, this kind of transaction — then maps the DPAN back to the real PAN so the right issuer can be reached.
   • Cardnet forwards the detokenised request to Bank Alfa — With the real PAN restored, Cardnet routes the authorisation request to Bank Alfa, the account's actual issuer.