| 摘要 |
PROBLEM TO BE SOLVED: To prevent unauthorized used of a credit card number in a member shop. SOLUTION: In each of a user information processor 100 (IC card) and an authentication dealer information processor 300, a substitute code SUBn consisting of a hash value of the credit card number, common data COMn, and secret algorithm ARGn are stored. In purchase by a user in a virtual mall of the member shop, the algorithm ARGn is applied to the common data COMn for generating a settlement identification code ID (n, i) inside the IC card, and the substitute code SUBn and the settlement identification code ID (n, u) are transmitted to the authentication dealer via the member shop. The authentication dealer authenticates the settlement on condition that the settlement identification code generated in the inside is coincident with the transmitted settlement identification code. The common data COMn are varied for each user, and the Algorithm ARGn generates a different settlement identification code in every payment. |
