Blockchain-based efficient and secure cloud cross-domain data sharing with dynamic revocation by multiple authorities

In complex cloud environments with expanding data volumes, coordinating the efficiency and security of data sharing is crucial to meet the practical needs of cross-domain sharing among users with distributed attributes from multiple domains. For example, in the context of smart city development, residential energy data can support academic research or optimize resource distribution to improve urban management. In such cross-domain sharing, secure data transmission and multi-party authorization are vital to ensure data security and compliance. This paper employs blockchain and Multi-Authority Attribute-Based Encryption (MA-ABE) to construct a high-security encryption system. It supports dynamic revocation under partial policy-hiding, verifiable lightweight operations, and resistance to offline dictionary attacks as well as multiple collusion attacks within the system. Smart contracts are used to enhance distributed attribute diversity and system robustness, while blockchain ensures transparency and security in key generation and dynamic revocation. Security, theoretical, and experimental analysis validate relatively low communication and computation costs of our scheme, with its high security, and significant performance advantages over current methods. © 2025 Elsevier B.V.