Method for operating mobile telephone, involves detecting whether cryptographic routine of trusted region is disrupted during execution, and setting non volatile backup when faulty operation counter reaches predetermined threshold value

摘要

The method involves providing a faulty operation counter in a volatile memory (10) to detect whether a cryptographic routine (8) of a trusted region (3) of a data processing device (1) is disrupted during execution. A non volatile backup is set when the faulty operation counter reaches a predetermined threshold value. The faulty operation counter is incremented or decremented depending on set or not-set flags. An interception of cache access times is carried out from an untrusted region (2) of the data processing device. Independent claims are also included for the following: (1) a computer program product comprising a set of instructions for performing a method for operating a data processing device (2) a data processing device.