Secure temporal-policy access control for time-correlated semantic communication in 6G edge networks

Semantic communication is expected to become a foundational technology in 6G edge intelligence networks, enabling end devices to transmit task-relevant semantic features rather than symbol-level data. However, semantic streams are highly time-correlated and often reveal latent identity or contextual information, making them vulnerable to inference attacks when processed by semi-trusted edge servers. Moreover, existing privacy-preserving mechanisms lack the ability to provide stateless, fine-grained temporal authorization while maintaining the ultra-low latency required by 6G applications. This work introduces T–PAC, a temporal-policy access control framework designed specifically for secure and privacy-preserving semantic streaming in 6G edge environments. T–PAC employs (i) time-indexed key derivation with embedded key transitions, enabling stateless per-timestamp decryption through lightweight authorization tokens; (ii) a semantic desensitization pipeline combining redaction, pseudonymization, generalization, and differential privacy to reduce semantic leakage; and (iii) a policy mapping mechanism that supports dynamic, window-bounded access control based on temporal requirements. Extensive experiments show that T–PAC achieves sub-microsecond encryption latency on desktop platforms and microsecond-level latency on resource-constrained edge devices, while maintaining compatibility with semantic feature processing. These results highlight the suitability of T–PAC as a secure foundation for next-generation 6G semantic communication systems.