Method for downloading software

摘要

A method for downloading software from a host device to an electronic device through a communication line, which, even when the download is interrupted, can simplify the procedure to restart the download while maintaining security. In the method, a certificate of authenticity data, which the card reader has obtained from the HOST computer, is stored in the non volatile memory. The download of the software from the HOST computer to the card reader is executed. The verification of authenticity data is obtained by calculation with respect to the downloaded software. This verification of authenticity data is then compared with the certificate of authenticity data obtained from the HOST computer, and the downloaded software is run when the certificate of authenticity data matches the verification of authenticity data.

主权项

1. A method for downloading software from a host device to an electronic device via a telecommunication line, the method comprising:
a step of providing an electronic device which comprises:
a first data storing means which stores a pre-update certificate of authenticity data in a first data storage area of said electronic device, the pre-update certificate of authenticity data certifying authenticity of pre-update software already loaded in the electronic device; anda second data storing means configured to store a second certificate of authenticity data in a second data storage area of said electronic device, the second certificate of authenticity data certifying authenticity of a second software to be newly loaded in the electronic device which will be obtained from said host device for updating the electronic device; a storing step in said second data storage area, in which, before starting a download of said second software to be newly loaded, said electronic device obtains said second certificate of authenticity data from said host device and stores said obtained second certificate of authenticity data in said second data storage area; a downloading step in which the download of said second software from said host device to said electronic device is executed; a data comparison step in which, after the download of said second software is completed, a verification of authenticity data, obtained by calculation with respect to said downloaded second software, is compared with said second certificate of authenticity data obtained in said storing step; a data storing step in said first data storage area, in which, when said second certificate of authenticity data matches said verification of authenticity data in said data comparison step, said second certificate of authenticity data is stored as the pre-update certificate of authenticity data in said first data storage area; and a run step in which, when said second certificate of authenticity data matches said verification of authenticity data in said data comparison step, said electronic device runs said downloaded second software.