A comprehensive and efficient CP-ABE scheme with full policy hiding and pre-decryption verification in peer-to-peer cyber-physical systems

Cyber-Physical Systems (CPS) are systems that deeply integrate physical entities with digital infrastructure. In CPS, the central processor and sensors collaborate through demand response to achieve real-time data processing. However, this demand response mechanism that does not require authorization to access may lead to the leakage of sensitive information, while wasting the local overhead of the entity and failing to meet the application requirements of peer-to-peer CPS. To address these issues, we propose a fully policy-hidden CP-ABE scheme based on Linear Secret Sharing Scheme (LSSS) access structure. The scheme uses the LSSS matrix to provide fine-grained access policies, but does not expose the mapping function \(\rho \). Instead, the information represented by \(\rho \) is converted into a blinded policy set to achieve full policy hiding, effectively preventing user privacy leakage. In order to avoid wasting user computing resources and improve decryption efficiency, the scheme provides permission verification before decryption. The cloud server can use private set intersection (PSI) technology to achieve attribute matching without knowing the policy, while helping users obtain the required decryption information and achieve decryption operations with minimal permissions and overhead. Security and performance analysis results demonstrate that our scheme satisfies the security requirements for data sharing in CPS while exhibiting good scalability.