A User-centric Data Sharing Scheme with Hidden Strategies and Revocation

Ciphertext-policy attribute-based encryption (CP-ABE) is a promising primitive to achieve fine-grained access control. However, the explicit access policies are prone to leaking its private information. Meanwhile, most existing schemes do not effectively support malicious user revocation. To solve the above issues, this paper proposes a user-centric data sharing scheme that supports policy hiding, fine-grained access control, and user revocation. The scheme uses CP-ABE to achieve fine-grained access control and hidden strategies. Binary tree structure is utilized to achieve malicious user revocation. The cloud server performs a search based on attribute matching to find users that match the access attributes of the data owner. From the experimental results, it can conclude that our protocol achieves user-centric security with performance advantages.