| 摘要 |
PROBLEM TO BE SOLVED: To perform change without matching with an existing cipher key. SOLUTION: In a card issuing machine, a card ID is generated (S1), a random number R is generated (S2) and whether or not it matches with respective existing keys inside a storage part 422 is checked (S3). When it matches, the random number R is generated again, and when it does not match for the card and when it is the first time, the R is written in a storage part 422 as a key K (S5), a step S2 is returned and the random number R is generated again. When non-matching is a second time, it is written in the storage part 422 as the key K' (S6) and secure data S are generated (S7). EK(S) is obtained by ciphering the secure data S by K (S8), F=0 and G=0 are defined, the card ID, K, K', F and S are sent to a card authentication center device 30 and ID, G and EK(S) are written in the card 10. |
