Method for managing a transaction with a smart card

A system for performing a contactless payment transaction comprising:

• a smart card allocated to a user;
• and
• a portable apparatus,
• wherein the smart card is configured to:
• successively receive a Get Processing Options command as defined by Europay Mastercard Visa (EMV) specifications from a point-of-sale terminal;
• send a response to the Get Processing Options command to the point-of-sale terminal;
• receive a Generate Application cryptogram (AC) command from the point-of-saleterminal, as defined by EMV specifications;
• send a response to the Generate AC command to the point-of-sale terminal:
• wherein the smart card is a banking card configured to establish a first communication link with the point-of-sale terminal in response to a first tap that occurs when the smart card is placed within a proximity to the point-of-sale terminal,
• wherein the smart card is configured to receive, through the first communication link, the Get Processing Options command comprising a transaction amount specific to a contactless payment transaction,
• wherein the smart card, in response to detecting receipt of the Get Processing Options command, is configured to turn on an internal battery embedded in the smart card, wherein turning on the internal battery is triggered exclusively by receipt of the Get Processing Options command, use power of said internal battery to send the transaction amount to the portable apparatus through a wireless communication channel, and record said transaction amount in a non-volatile memory embedded in the smart card, and turn off the internal battery,
• wherein the portable apparatus is configured to provide the user with the transaction amount in response to receiving said transaction amount to enable user verification of transaction amount outside of the point-of-sale terminal's control;
• and
• wherein the smart card is further configured to:
• detect a subsequent second tap;
• establish a second communication link with the point-of-sale terminal;
• receive, through the second communication link, the Generate AC command which requests agreement of the smart card for completing said contactless payment transaction;
• resume said contactless payment transaction upon receipt of the Generate AC command;
• and
• compute a response to the Generate AC command using the transaction amount stored in the non-volatile memory embedded in the smart card that was received through the first communication link to provide cryptographic authentication based on the independently verified transaction amount.