Patent ID: 8770476

Claim:
A reader comprising: a contactless interface; a transaction module coupled to the contactless interface, wherein the transaction module is configured to minimize an interaction time under 500 milliseconds for a contactless transaction between the reader and a card by: wirelessly sending from the reader to a card in a command message a terminal unpredictable number, transaction amount, and transaction currency; receiving from the card in response to the command message a wireless message with a dynamic signature generated based on an application transaction counter (ATC), the terminal unpredictable number, the transaction amount, the transaction currency, and a card unpredictable number, the dynamic signature sent with an application file locator (AFL); and then wirelessly transmitting from the reader to the card a read record command message to request one or more records indicated in the AFL from the card; and receiving from the card the requested one or more records requested by the read record command; and a security module, coupled to the transaction module, configured for: recalculating the dynamic signature; and authorizing the contactless transaction if the dynamic signature received from card is validated.