Research On Efficient Query With Access Control On The Ciphertext In The Cloud

The data owner encrypts and outsources sensitive data to the cloud server for users to share and access it anywhere. Thus, maintaining the security of the cipher texts and supporting efficient queries by multi-user with different access authorities have become the main problems of multi-user applications on the outsourced data in the cloud environment. However, the existing encrypted query technologies and access control measures are not fully suitable to the application scenarios of multi-user with different access authorities in the cloud environment.Considering that the existing encrypted query technologies cannot support the efficient encrypted range queries and access control at the same time, a RA-tree based constructing method of encrypted indexes is presented, and the access control is added to the constructing, and the efficient query system with access control on the cipher texts is designed; Considering that the existing encryptions which encrypt indexes and queries are not fully suitable to the application scenarios of multi-user in the cloud environment, the characteristic of the unilateral inverse matrix existing non-unique unilateral inverse is employed to encrypt the index tree and queries, and to ensure the security of index tree; Considering that the existing access control methods cannot support the efficient encrypted queries of multi-user, the key derive is applied to encrypt the RA-tree based index tree with access control and grant access authorities to users. Accordingly, the efficiency of encrypted queries with access authorities is ensured; the efficient query system with access control on the cipher texts is implemented, and then the constructing of encrypted indexes and the efficient query on the encrypted indexes are completed.Finally, the accuracy and security of the system are analyzed, and the experiments are presented to evaluate the accuracy and performance. The results show that RA-tree queries are suitable for the applications of multi-user with different access authorities and more efficient than ABE-based access control encryption methods.