Efficient Attribute Revocation in Attribute Encryption Based on Time-Stamped Local Keys

With the explosive growth of large-scale data sharing and dynamic access requirements, traditional ciphertext-policy attribute-based encryption (CP-ABE) faces significant efficiency bottlenecks when dealing with attribute revocation and timesensitive access. The TR-LK (Time-tagged Revocation with Local Key) model proposed in this paper embeds time tags on both the key and policy sides, and is supplemented by a local incremental update mechanism to achieve fine-grained attribute invalidation without global re-encryption. Local experiments are carried out in three real scenarios: MIMIC-III medical dataset, medium-scale IoT logs, and hybrid cloud shared directories. Compared with mainstream solutions such as AC-PABE (Sun et al., 2013), R-ABE (Ge et al., 2023), and RS-ABE (Yang et al., 2024), TR-LK reduces revocation delay, decryption delay, and communication overhead by an average of 59.3%, 62.7%, and 63.4%, respectively, and natively supports replay attack defense. The results show that TRLK can provide efficient, secure and scalable access control support for cloud services, IoT and smart healthcare where user attributes change frequently.