Security Module Global Management Message Enforcement
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Solution Overview
Problem
Existing methods for verifying correct reception and execution of management messages by security modules in multimedia receivers are prone to risky key changes, especially during global updates, which can be time-consuming and costly, particularly when multimedia receivers are disconnected.
Innovation Solution
A method that enforces the processing of positive addressing management messages by a security module only after successful processing of global management messages, ensuring that access to broadcast services is renewed only when the previous global management messages have been correctly processed, thereby avoiding risky key changes and simplifying secure global updates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If global management messages are processed to update security modules, then security updates are achieved, but time-consuming key changes occur especially when receivers are disconnected
Solution Approach 1:
The patent applies preliminary action by requiring security modules to process global management messages (G-EMMs) before processing positive addressing management messages (PA-EMMs). This sequencing ensures that key updates and security parameter changes are completed in advance, so when receivers are disconnected and later reconnected, the security modules already have the updated keys and can process service authorization quickly without time-consuming key changes during service restoration.
2Ease of operation
If positive addressing management messages are processed independently, then service access is maintained, but fraudulent access by dishonest subscribers may occur
Solution Approach 1:
The patent requires that positive addressing management messages (PA-EMMs) be processed only after global management messages (G-EMMs) have been successfully processed. This preliminary action ensures that security modules have the latest security parameters and key information before authorizing service access. This sequencing prevents fraudulent access because even if a dishonest subscriber tries to process PA-EMMs independently, the security module will reject them until the required G-EMM processing is completed, maintaining both access continuity for legitimate users and security against fraud.
3Reliability
If key changes are performed during global updates, then security is enhanced, but the process becomes time-consuming and costly
Solution Approach 1:
The patent performs key changes and security parameter updates as preliminary actions within the global management message processing phase, before service authorization occurs. By completing key changes in advance during G-EMM processing, the system enhances security without making the service access process time-consuming. When receivers are disconnected and later reconnect, the key changes are already complete, avoiding prolonged service interruption and reducing the time cost of key changes.
Data Source
Figure 1
AI summary
A method to enforce processing of management messages by a security module associated to a multimedia receiver configured to receive broadcast access controlled multimedia services, the management messages being transmitted by a managing center to the multimedia receiver. The method comprises steps of: receiving by the security module at least one global management message addressed to a plurality of multimedia receivers operated by the managing center, tracing processing of said global management message, receiving at least one positive addressing management message addressed to said security module, checking, by the security module, anterior processing of the global management message through the value of the parameters set during tracing processing of the global message, processing the positive addressing management message only if previous checking gives a result indicating a successful enforcement of the global management message allowing the multimedia receiver accessing the broadcast multimedia services.