| 摘要 |
In a mobile communication system, communication credits are stored in a secure module 30 of a mobile communication appliance 10. Credits are reloaded over-the-air (OTA) from a reload server 20. For requesting a reload, the secure module 30 generates an authenticated reload request message 50, which is transmitted to the reload server 20. In response to receiving the reload request message 50, the reload server 20 informs the secure module 30 of how many credits have been granted in the form of an authenticated reload grant message 60. Successive messages are made to differ by using different transaction numbers. A received authenticated message is only accepted if a transaction number in the message matches a local transaction number. |
