Method for securing a mobile wireless apparatus against unauthorized use.

摘要

The method involves connecting a subscriber identification module, code card, to a mobile radio to allow data exchange. After input of a device code, the system is initialised. A number is transmitted from the mobile to the ID module. There, an authentication parameter is calculated from the number, using a code or key stored in the module and this is transmitted to the mobile. The latter stores the number and parameter as duplets in a non-volatile memory. During operation, a personal identification number is input to the radio for authentication checking. The duplet-stored number is transmitted to the ID module. An authentication parameter is calculated and transmitted to the mobile. In the mobile, the transmitted parameter is compared with the stored parameter. If they do not match, further operation, especially making connections, is blocked. If the parameters match, the mobile is freed for use.