A Practical Attribute-Based Document Collection Hierarchical Encryption Scheme in Cloud Computing

Description

Encryption can provide fine-grained access control and secure data sharing to the data users in cloud computing. The encryption/decryption efficiency of existing schemes can be further improved when encrypting a large document collection. Ciphertext-Policy Attribute-Based Hierarchical document collection Encryption scheme named CP-ABHE. CP-ABHE is more efficient in both computation and storage space without sacrificing data security. The greedy strategy to build the trees incrementally and grow the trees by dynamically combining the small ones. All the documents on an integrated access tree are encrypted together. Different to existing schemes, the leaves in different access trees with the same attribute share a same secret number which is employed to encrypt the documents. The security of our scheme is theoretically proved based on the Decisional Bilinear Diffie-Hellman assumption. CP-ABHE performs very well in terms of security, efficiency and the storage size of the ciphertext.