Abstract: In the paradigm of database outsourcing，query integrity means that the client query result set returned from the server side must be both correct and complete，i.e.，all the records are original without any modification and all the records satisfying the query are returned without any omission.A novel scheme named“duplicate table” is proposed to verify the completeness of query result set.For each table at the server side，a duplicate table is given，which is encrypted by different encryption scheme or encryption key.Thus，the server cannot easily distinguish the original table from the duplicate one.When querying，the client queries the two tables separately and compares the two query result sets to verify whether all the records satisfying the query are returned from the server.Experiment results show that the scheme is efficient and feasible.

Key words: database outsourcing, security, integrity, query completeness

摘要： 在外包数据库中，查询完整性意味着从服务器返回给客户的结果集是正确的和完全的，即所有的记录都是来自数据拥有者且没有经过任何修改的，同时所有满足查询的记录都返回到客户端而没有遗漏。提出了一个称为“重复表”的新方法来检验查询完全性。在服务器端，每个表都有一个重复表，该表用不同的加密方法或加密密钥加密。从而，服务器不能从数据本身区分原始表和重复表。在查询时，客户分别查询原始表和重复表，得到两个结果集，然后判断是否所有满足查询的记录都出现在结果集中。实验结果表明该方法是有效的。

关键词: 数据库外包, 安全, 完整性, 查询完全性