Efficient Key Update for Secure Data Sharing in Industrial Cloud Access Control

In the Cloud of Things, privacy-preserving and efficient data sharing is most critical for industrial systems, whose sensitive information needs to be kept secure against background dynamic access requests. Ciphertext-Policy Attribute-Based Encryption (CP-ABE), a strong fine-grained access control mechanism, suffers from extreme challenges in attribute revocation with high computational and communication overhead caused by comprehensive ciphertext re-encryption and key redistribution. For that purpose, the paper introduces a Secure Data Sharing System incorporating CP-ABE with Attribute Certificates (ACs) and a hybrid RSA/AES encryption system. It supports scalable access control by AC revocation using dynamic update in ACs for attribute revocation, with re-encryption of the entire data set being avoided and processing being reduced to lower costs. There is also a delegated key update distributed from the central authority to optimize system efficiency as well as scalability. Built for factory cloud environments, the system relies on a Firebase backend for the storage of real-time data, and it includes secure interactions with smart edge devices and cloud systems. Graphical and command-line interfaces are intuitive, making access easy. Experimental tests show that a $98 \%$ accuracy exists in access controls, revoking attributes in 0.3 seconds per user, and providing efficient encryption capabilities for datasets sizes up to 10 MB. These findings confirm the system’s applicability to large-scale industrial use, although scalability issues for very large datasets and sophisticated policy support indicate areas for future optimization.