摘要 |
Methods are described for performing a timely authorization of digital credential data delivered from a mobile device that is without access to a local persistently stored permanent cryptographic key; through an interrogation with a point-of-sale that behaves according to the direction of a card specification; wherein the card specification expects the mobile device to create a cryptogram that is calculated, at least in part, using the permanent cryptographic key and, at least in part, from unpredictable data delivered from the point-of-sale to the mobile device during the interrogation. |