US Patent 7222783 Secure transfer of data between two smart cards

A device external to a terminal transmits a specific application identifier and an encrypted first key and number to a first chip card in service in the terminal. In the first card, if the decrypted first number satisfies a first condition, the specific application is called up, application data are read, the data are encrypted using the decrypted first key to transmit them to the external device, and the application is made inoperable. Following replacement of the first card by a second card, the external device transmits the identifier and an encrypted second key and number to the second card. In the latter, if the decrypted second number satisfies a second condition, the encrypted data are transmitted to the second card so that the latter calls up the application, decrypts the encrypted data using the decrypted second key and installs said data.