Portable object such as an electronic purse for payment in different currencies and associated payment protocol

摘要

The invention concerns a portable object comprising an electronic purse application, wherein said data-exchange protocol defines an instruction for operating electronic currency conversion. The method consists in: (a) storing in the portable object an electronic currency conversion table certified by an original electronic signature (SK) by a banking authority; (b) authenticating said conversion table, and, on the basis of said conversion table authentication, the currency conversion rate value constituting an authenticated conversion rate value; (c) carrying out the conversion of the electronic purse current balance, from said authenticated conversion rate value, to generate a converted current balance value, and storing the converted current balance value, or, in the absence of authentication, (d) stopping the current transaction and sending an error message.