Abstract:Attribute-based encryption (ABE) enables fine-grained access control based on user attributes, but it relies on a centralized authority for key generation, which may cause security risks such as key leakage. Registered-based encryption schemes mitigate this issue using mechanisms such as user registration and public key aggregation. However, existing constructions based on multiple parallel sRABE sub-schemes require frequent public key re-aggregation when users dynamically join or leave, leading to computational and storage overhead that grows linearly with the number of sub-schemes. Therefore, these constructions are difficult to apply in scenarios with frequent user changes. To overcome this limitation, this study proposes a chameleon-hash-based revocable registered attribute-based encryption scheme that achieves efficient user registration and revocation within a single sRABE framework. By introducing a trapdoor-controllable chameleon hash function and allowing the public key aggregator to maintain public key consistency, new users can be registered without system-level public key re-aggregation. Meanwhile, user revocation only requires marking the status of registration slots, thus avoiding the computational overhead caused by the multi-sub-scheme structure. In terms of efficiency, the computational overhead of the new-user registration phase is analyzed, and the results show that the computational complexity of this process depends only on the number of user attributes and is independent of the number of users in the system. Security analysis shows that the proposed scheme is secure against chosen-plaintext attacks under the indistinguishability model.