Patent attributes
Techniques for authenticating a contactless smartcard in a card processing system are disclosed. A card reader measures an impulse response associated with the contactless smartcard during outbound modulation of an RF carrier and compares measured impulse data to reference impulse data. The reference impulse data can be stored at the card reader or obtained from the contactless smartcard in an encrypted form. Optionally, the card reader issues one or more challenges to the contactless smartcard in connection with a card transaction and verifies a response to the one or more challenges using calibration data. The card reader can determine the card's authenticity based on the impulse data, the response to one or more challenges, or a combination thereof.
