Abstract: This article introduces the main concept of private information retrieval, trusted computation and the concept of PIR based on TC. It also gives some existing model of PIR based on TC and performance, and finally creates a new model in order to further improve SC’s complexity of creating a shuffled database from O(N3/2) to O(cN), where c is a constant greater than 1.

Key words: Private information retrieval(PIR), Trusted computation(TC), Secure coprocessor(SC)

摘要： 介绍了私有信息获取和可信计算的概念，由此引出了基于可信计算PIR的概念并列举了几种现有模型及其性能，并为进一步提高PIR的性能提出了一种新的模型，该模型可以把安全处理器(SC)读写数据库的时间复杂度从O(N3/2)降低到O(cN)，其中c是大于1的
常数。

关键词: 私有信息获取, 可信计算, 安全处理器