Intelligent Re-encryption and Commitment-Driven Dynamic Data Sharing

Data sharing has become a crucial requirement for current cloud-based collaborative computing. However, traditional data sharing mechanisms encounter the critical challenge of balancing privacy and efficiency, since current solutions struggle with scalability bottlenecks in multi-user authorization and vulnerable to policy reverse-engineering attacks. In this work, we present a policy-hiding proxy re-encryption scheme to overcome limitations in existing centralized and policy-based architectures. Our scheme proposes a hierarchical cryptographic framework where access policies are irreversibly hashed to prevent structural inference, while semi-trusted proxies perform constant-time ciphertext conversion using bilinear pairing-based re-encryption keys. Moreover, the proposed scheme ensures end-to-end confidentiality without compromising cross-domain sharing efficiency, which decentralizes key management through hardware-secured modules and embeds lightweight integrity verification via Pedersen commitments. Experiment evaluations have demonstrated that our scheme has an excellent performance in maintaining sub-millisecond latency for large-scale data while achieving resistance against adaptive attacks.