Efficient XQuery over encrypted XML documents

Data plays an important role in today´s business activities. In order to share information, data is outsourced occasionally, usually in the form of Extensible Markup Language (XML) files which may contain sensitive information only intended for specific audiences. Securing the data is, as a result, of the utmost importance. Several techniques are used for this purpose, with encryption being the most powerful method. The major disadvantage of using encryption is that it reduces the performance of those queries which perform operations on encrypted data. In this paper we propose a technique that significantly improves the performance of range XQuery on encrypted XML data. Results show that the proposed technique is more efficient than the state-of-the-art technique.