| 摘要 |
PROBLEM TO BE SOLVED: To prevent the misuse o a transaction medium by setting authentication precision according to the possessing amount of the transaction medium whose possessing value varies each time of transaction use so as to improve authentication precision with the increase of the possessing amount of this transaction medium. SOLUTION: An electric cash payment storing part 23 stores electronic cash paid by shifting a value from an electric wallet card 12 by transaction use. At the time of paying processing, an authentication request part 25 selects required authentication processing from the remainder of the electronic cash and remainder information in an authentication information storing part 24 to request optimum authentication processing. In this case, the part 25 changes the setting of authenticating precision so as to obtain authentication precision suited to the card 12 according to the possessing amount of the electronic cash possessed by the card 12. For example, at the time of changing the setting by increasing the number of the inputting figures of a password from four figures (a normal authentication level) to eight figures (high authentication level) with the increase of the possessing amount of the card 12, the authenticating precision with a transaction user is improved. |
