Abstract: The structural characteristics of XML database document have been fully made use of and combined with the encoding theory of Dewey code to design an encrypted XML algorithm called Index Layered Itersection Scan Algorithm (ILISA) under the model of Database as A Service (DAS). The data retrieval of tree structure was turned into the data retrieval of sequential list form. The authors applied the interpolation search algorithm instead of depth-first or breadth-first search, which had brought a good time complexity. And a data structure of XML index table was designed to reduce the search space greatly. Finally, the complexity of ILISA was described and the efficiency of ILISA was proved.

Key words: Database as A Service (DAS), XML, encryption, data querying, E-commerce

摘要： 充分利用XML数据库文档的结构特性，结合Dewey编码的编码原理，设计了一种数据服务（DAS）模式下的XML加密数据的查询算法（ILISA）。将树型结构上的数据检索变换为顺序链表的数据检索，应用插值搜索算法替代深度与广度优先遍历，带来了良好的时间复杂性。设计了一种XML索引表数据结构，使得检索空间大幅缩减。最后给出ILISA的复杂性描述，证明了该算法具有良好的效果。

关键词: 数据服务, XML, 加密, 数据查询, 电子商务