Portable Data Carrier Status Tracking for Unauthorized Read Detection

The patent applies preliminary action by pre-modifying the status information in memory during the first read access to confidential data. The processor unit automatically changes the status information from an initial state (e.g., all zeros) to a modified state (e.g., containing a non-zero value or specific pattern) when reading occurs. This pre-prepared status change enables later verification of whether unauthorized access happened, resolving the contradiction by making read access detectable while maintaining security through controlled access procedures.

The patent applies local quality by implementing status information tracking only for specific confidential data subsets rather than all data. The status information is stored in memory locations associated with particular data regions, and the processor unit modifies only the relevant status information when reading confidential data. This selective approach enables read access detection for sensitive information while avoiding the complexity of tracking all data accesses, thus resolving the contradiction between detection capability and device complexity.

The patent applies self-service by implementing automatic status information modification through the processor unit during read operations. When the processor unit reads confidential data from memory, it automatically detects the read operation and modifies the associated status information without requiring external intervention or complex control logic. This automation maintains ease of operation for authorized users while reliably detecting unauthorized access attempts, resolving the contradiction between reliability and ease of operation.