摘要 |
A method for monitoring execution of a sequence of data processing program instructions in a security module associated to a multimedia unit connected to a managing center supplying control messages authorizing access to broadcast data streams. The security module comprises a processor for executing the instructions, a memory, and a monitoring module for analyzing the instructions before execution by the processor. The managing center comprises a security module emulator generating reference data sets by executing a sequence of instructions induced by data of a given control message in the program. The reference data sets are appended to control messages sent to the security module. The monitoring module analyzes a sequence of program instructions for determining a check data set which is compared with a reference data set received from the control messages. When the reference and check data sets match, the program continues executing. Otherwise, further control message processing stops.
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