| 摘要 |
The invention provides a method for protectedly debiting an electronic payment mechanism, such as a telephone card. In the communication protocol between the payment mechanism and a payment station, an authentication is used to identify the payment mechanism during various steps of the protocol. According to the invention, the authentications are mutually related by states of a cryptographic process in order to be capable of detecting an interference in the protocol. The method may be applied to existing payment cards having a dynamic memory, it being guaranteed that the contents of the dynamic memory, in which there is located information related to the authentication, is not lost during the protocol. |
