Abstract: The secure query is that a user of a database can accomplish a query without revealing the user and database’s private information. This paper presents two methods of secure query: (1)The first scheme is a protocol of secure two-party computation, which is based on the equijion protocol. Although it has high security, the first scheme has too high cost and it is too difficult to use in large database. (2)The second scheme introduces the software as a trust third part and prevents the user and database from disclosing privacy. Although the security is lower than that of the first method, the second method has lower cost and it is more practical.

Key words: Secure multi-party computation, Private information retrieval, Safety query

摘要： 安全查询是指参与查询的用户一方与拥有数据库的一方在各自的私有信息互不泄露的情况下，完成查询操作。该文描述了解决查询问题的2套方案：方案1基于两方的安全计算协议，尝试将Equijoin协议应用于安全查询问题。虽然该方案安全性能高，但是由于加密通信代价太大，因此很难适应对大型数据库的查询；方案2将软件作为可信第3方的协议，只要该软件不被破解，就可确保查询用户与数据库的信息不被泄漏，尽管其安全性低于方案1，但运行代价低，方案2是一个实用的解决方案。

关键词: 安全多方计算, 私有信息检索, 安全查询