The Research Of Database Encryption Retrieval In Cloud Storage

Simple database in the cloud storage outsourcing model is client and server, the client upload local encrypted data to the cloud server, the server to save data and the data retrieval, and so on. This model while guarantee the encrypted data will not leak clear data to the server, but when the ciphertext data retrieval, need to decrypt the ciphertext data for a large number of, cause the client too much overhead. In the DAS model, range query and fuzzy match is inefficient because the ordering, similarity,comparability is destroyed by encryption. According to the above problem, this paper make the following improvements:(1) To address the problem of the encrypted data retrieval in the DAS model, we propose an encrypted data retrieval scheme with the proxy in the DAS model. we add the agent in client, and transform the data from client by Random Space Encryption(RASP) approach in the proxy. Because of the reversible of RASP, the proxy only need to save the encryption key. It not only reduces the overhead of creating index in client,but also can prevent information leakage from index label.(2) In client, we create a multidimensional bucketization index, it has a substantial reduction for decryption in overhead. At the same time, for query the numeric data, user can query multidimensional range by bucketization index.(3) To address the problem of privacy leak by Multi-user access, we add an privacy-protect index to record in DBMS, it solves effectively the problem of unauthorized access of users in DAS model. we partition the data to different sets by vertex coloring, tuples in different clusters are assigned different salts,tuples in the same cluster are assigned the same salt,it can be able to distinguish access permissions between different users. So, it effectively prevent the data leakage.We finally on the optimal scheme for dividing the multidimensional barrels,discovering multidimensional barrels, effectively improve the query efficiency, and has carried on the Matlab code to RASP method test, found the ciphertext data retrieval based on agent improved the security of the DAS model effectively.