Patent ID: 9613354
Date: 2017-04-04
CPC Classifications: G06K,G06Q,G07F

Claim:
1. A method comprising: sending from a reader to a payment device a terminal unpredictable number and a transaction amount; receiving from the payment device a message with a dynamic signature generated based on an application transaction counter (ATC), the terminal unpredictable number, and the transaction amount, the dynamic signature sent with an application file locator (AFL); and then transmitting from the reader to the payment device a command message to request one or more records indicated in the AFL from the payment device; receiving at the reader from the payment device the requested one or more records requested by the command message, wherein the one or more records requested by the command message is received at the reader within 500 milliseconds of the reader sending the terminal unpredictable number and the transaction amount to the payment device; and causing a recalculation of the dynamic signature in order to authorize a transaction if the dynamic signature received from the payment device matches the recalculated dynamic signature.