Conditional Access Signature Verification for Glitch Attack Prevention

The patent applies preliminary action by performing redundant operations during EMM processing to build signature values before final authentication. These redundant operations (such as multiple cryptographic computations or verification steps) are executed in advance to ensure that even if a glitch attack occurs during critical authentication steps, the pre-computed signature values will detect the tampering and prevent unauthorized access. This resolves the contradiction by prioritizing security reliability over minimal processing complexity.

The patent applies partial or excessive action by implementing redundant operations that perform more computational work than strictly necessary for basic EMM processing. These excessive operations include generating signature values through multiple cryptographic computations or verification steps that go beyond the minimum required for authentication. While this increases processing time, it ensures that even partial execution due to glitch attacks will produce detectable inconsistencies, thus resolving the contradiction between authentication integrity and processing time by accepting some time loss as necessary for security.

The patent applies the intermediary principle by introducing signature values as a mediating element between EMM processing and authentication decisions. Instead of directly verifying authentication credentials, the system first computes signature values from redundant operations during EMM processing, then uses these signature values as intermediaries to verify whether the processing was completed without glitch attacks. This intermediary layer simplifies the overall system architecture by providing a clear verification mechanism that separates the complex redundant computations from the final authentication logic, thus resolving the contradiction between access control security and system architecture complexity.