| 摘要 |
<p>PURPOSE:To avoid errors and illegal access to defining information by identifying an operation-enable or -unable state based on the identifying information stored in a nonvolatile memory forming an IC card to enable access to the area defining information in the operation-unable state and to unable said access in the operation-enable state respectively. CONSTITUTION:A IC card contains a control element 11, an erasable nonvolatile memory 12, a program memory 13, and a contact part 14 where electrical communication is secured to an external device. The memories 13 and 12 consist of a mask ROM and an EEPROM respectively. The memory 12 includes an identifying information area 21 of a single byte, for example, an area defining information area 22, and a user area 23. Then the identifying information is written in the area 21 to identify an operation-unable state, i.e., an unproduced state of information or an operation enable state, i.e., a produced state of information. The area 22 functions to control the area 23 after dividing it into plural parts. The area 23 stores various data. In such constitution, no illegal access occurs after an operation enable state is set.</p> |
