基于错检期望值的密文索引技术

Cryptograph Index Technology Based on Wrong Hit Expectation

如何提高密文数据库的查询效率是数据库加密技术面临的一个主要问题.密文索引技术是提高数据库中密文查询效率的手段之一,但现有的密文索引方法存在查询命中率低和信息泄露衡量问题.本文首先根据查询概率的实际分布情况,提出整体错检期望值的概念,以此为基础提出一种适用于非等概率查询的复合桶划分密文索引技术,并给出了相应的密文查询策略.然后,针对密文索引的信息泄露问题给出衡量和消减方法.最后,通过实验对算法进行了分析和验证.

How to improve the query efficiency in cryptograph database is a primary problem of database encryption technology. Cryptograph index technology is one of the methods to improve cryptograph query efficiency in database, but there are many problems in cryptograph index methods such as low query hit rate and information disclosure measure. At first, basing on the actual distribute condition of query probability, the conception of whole-wrong-hit expectation is proposed, and a complex-bucket-partition cryptograph index technology that adapts for unequal-probability query and cryptograph query strategy are proposed. Then, a measure and an elimination method are presented focus on the detecting problem of cryptograph index. Finally, the algorithm is analyzed and validated by experiments.