A Lightweight and Efficient Elliptic Curve Cryptography Based File Hierarchy Attribute-Based Encryption Scheme with Enhanced Security and Cross-Domain Data Sharing

In cloud computing, ciphertext-policy attribute-based encryption (CP-ABE) is widely adopted for secure data storage and flexible fine-grained access control. For collaborative scenarios involving hierarchical file structures, file hierarchy CP-ABE (FH-CPABE) schemes have been proposed. However, existing file hierarchy CP-ABE schemes rely on computationally intensive bilinear pairing operations, resulting in high overhead. To address this issue, this paper proposes ECC-FH-CPABE, a lightweight and efficient file hierarchy CP-ABE scheme based on elliptic curve cryptography (ECC). By replacing bilinear pairings with scalar multiplication on elliptic curve points, our scheme achieves superior computational efficiency while reducing communication overhead. To ensure strong security while maintaining lightweight performance, this scheme introduces ECC-based data noise to resist user collusion attacks. In addition, ECC-FH-CPABE supports cross-domain data sharing with efficient batch operations, relieving performance bottlenecks. Security analysis proves that the scheme is secure against chosen-plaintext attacks. Extensive simulation results show that ECC-FH-CPABE significantly improves both computational efficiency and communication efficiency compared to existing schemes.