A Lightweight and Generic Access Rights Update Mechanism for Attribute-Based Encryption in cloud storage

Cloud storage has emerged as a foundational tool in managing massive volumes of sensitive data across diverse domains. Attribute-Based Encryption provides fine-grained access control to encrypted data in these scenarios. However, the practical application of ABE in cloud environments faces significant challenges, including lack of a generic mechanism for updating access rights and inefficiencies in handling large-scale data. Existing methods suffer from high computational overhead and rely heavily on fully trusted clouds, limiting scalability and increasing privacy risks. To address these challenges, we propose a Lightweight and Generic Access Rights Update Mechanism (LGUM) for ABE. LGUM offers a universal framework for access rights update, leveraging precise ciphertext update components to minimize computation and communication costs. It supports efficient multi-user access rights update with constant complexity $O\left(1\right)$, eliminating reliance on fully trusted clouds. And then, we exhibit its generality across various ABE paradigms, including CP-ABE and KP-ABE. Comprehensive performance evaluations demonstrate significant reductions in communication and computational overhead compared to existing approaches, with formal security guarantees based on the BDH and MBDH assumptions.