| 摘要 |
PROBLEM TO BE SOLVED: To prevent an IC card from being illegally accessed even when the partial wire tapping of information in a special memory packaged in an IC card is permitted. SOLUTION: When an IC card 1 is inserted to an IC card reader/writer 3 and the cancel of access right is requested from the reader/writer 3, an arithmetic processing part 15 reads a random number from a random number generating processing part 11 and translates it to the memory address of a special memory 7. Then, a data read request is sent so as to read the data of that memory address out of the special memory 7 and to send them to an IC chip 5. The data from the reader/writer 3 are compared with data in a special memory managing table 17. When both the data are equal, the right of access is canceled to the readar/writer 3 and it is reported. When these data are not equal, an access right cancel error is judged and it is reported to the reader/ writer 3. At the same time, an access right cancel error counter 21 is activated and increment operation is performed. When it is reported from the counter 21 a count value reaches a prescribed threshold value, it is reported through the reader/writer 3 to a center host and the IC card 1 is locked by itself. |
