| 摘要 |
PURPOSE:To prevent privacy data in an electronic card from being easily read and written by transmitting transmission control procedures from a host device to the electronic card and accessing data in the electronic card in accordance with transmission control procedures. CONSTITUTION:A microprocessor system 16 reads out and executes a program which loads transmission control procedures from a loader storage area 12, and specific transmission control procedures are stored in a transmission control procedure storage area 13 from the host device 19 through a reception line 18. The transmission control procedure program is read out from the area 13 and is executed, and data is written on a privacy data storage area 14 from the host device 19 through the reception line 18 in accordance with specific data transmission control procedures, and privacy data is read out from the area 14 and is transmitted to the host device 19 through a transmission line 17 in accordance with specific data transmission control procedures. Since the host device 19 reads and writes privacy data from and in a nonvolatile memory in accordance with specific transmission control procedures after storing these procedures in an IC card 11, a data transmission control means is certainly changed each time when privacy data is read or written. |
