A novel model for query over encrypted XML databases

In recent years, there has been increasing concern about ¿database as a service¿(DAS) architectures. Data security is the overriding concern in DAS, and encryption is a natural solution. However, queries over encrypted databases are usually inefficient due to a heap of time on the encryption and decryption. In this paper, we present an encryption scheme and XQuery translation model of XML database. The major work and contribution of this paper are as below: 1) Splitting method is proposed in the encryption scheme, in which more flexible encryption granularity is obtained. 2) We put forward the encryption strategy that, by encrypting two or more fragments together, is efficient to resist various kinds of database attack owing to the changed ciphertext distribution and data size by splitting. 3) An XQuery translation model is introduced, by converting the query of XML data into that of relational data, combined with XML schemas compression and hash technology, which perform the XQuery language efficiently. Our experimental evaluation shows that our XML database encryption and query model achieves both excellent query efficiency and robust security.