| 摘要 |
A process and system are disclosed for generating a credit by means of a prepaid voucher, as well as the voucher used therefor. A client generates a credit with a service provider in that he transmits to the service provider a secret character string stored on the prepaid voucher. Every time the client requests a service from the service provider, the value of the service is debited from his credit. In order to achieve the highest possible security standard, the secret character string stored on the prepaid voucher contains a secret access code which is stored nowhere else. The secret access code is generated by the emitter of the prepaid vouchers from a data set and a number associated with said data set, preferably a random number. The secret access code is stored together with the random number as a character string on the prepaid voucher and protected by appropriate measures against illicit access. The secret access code is destroyed as soon as it is stored on the prepaid voucher. The random number and the data set are transmitted to the service provider, who stores them in a data bank so that the corresponding data set may be accessed by means of the random number. |
