A method and a system are provided for authenticating secure payment card transactions and verifying and validating payment card user identities. The method includes determining a numeric or alphanumeric code on a vehicle registration plate of a vehicle (e.g., a driverless vehicle or a drone) bearing a processing device that is approaching a payment area (e.g., a toll road, a refueling station, or a retail store). A wireless communication circuit (e.g., Near Field Communication (NFC) circuit) is communicatively coupled to the processing device. The method also includes determining a numeric or alphanumeric identification of the processing device; comparing the numeric or alphanumeric code on the vehicle registration plate with the numeric or alphanumeric identification of the processing device to determine whether or not an association exists between the vehicle and the processing device; and assessing the determined association to facilitate determining whether a payment transaction using the processing device is valid or invalid (e.g., potential fraud).