A Multi-Authority Attribute-Based Encryption Scheme with Attribute Hierarchy

The existing attribute based encryption with attribute hierarchy program has only one authority, which causes serious performance bottlenecks. In order to solve the problem in hierarchical attribute based encryption, we proposes a multi-authority hierarchical attribute based encryption scheme. The scheme removes the trusted central authority, and prevents the communication between authorities, thereby ensuring the users' privacy and improving the system performance. We require that all the attributes in the system construct the attribute trees, and any attribute is represented by the attribute trees and the attribute path, which ensure that the users and ciphertexts attributes quickly matching. A user must have satisfactory attributes in order to decrypt. Additionally, we propose a more reasonable way of dividing attribute trees by using hierarchical clustering algorithm. Finally, we give out the correctness analysis and performance comparison analysis of the scheme. It meets the security of IND-sAtr-CPA based on the DBDH assumption in the standard model.