支持快速查询的数据库加密方法研究

为了解决数据库中加密字符串数据的查询问题。提出了为待加密的字段建立辅助索引字段的两阶段查询方法。索引字段的内容由原始数据的划分值和特征值两部分组成，它可以用来支持字符串数据的精确匹配查询和模糊匹配查询。查询加密数据时，首先利用索引字段对加密数据进行一次粗糙查询，然后在解密的数据上再进行一次精确查询。实验表明，其性能较传统的先解密后查询方法有较大的提高。

Practical Techniques for Fast Searches on Encrypted String Data in Databases

To solve the problem of querying on encrypted string data in databases,an auxiliary index column is built for each attribute need to be encrypted, which will be used in two-phrase query. The contents of the index column are corn posed of two different parts. The first part corresponds to the partition value of the encrypted string data, which will be used in the exact match query. The second part corresponds to the feature value of the encrypted string data, which will be used in the fuzzy match query. When querying data,coarse query is performed first on the encrypted data based on the index column,which filtrates those records not related to the query conditions. The remaining records will be decrypted, and refined query is performed on the decrypted data. Results of a series of experiments validate the functionality and usability of the approach.