A Cryptograph Index Technology Based on Wrong Hit Expectation

How to improve query efficiency in cryptograph database is an essential problem in database encryption technology. As one kind of methods for improving cryptograph query efficiency in database, existing cryptograph index technologies suffer from two main problems: low query hit rate and lack of information disclosure measures. In this paper, we propose a new cryptograph index method based on the probability distribution of queries. We first define the conception of whole-wrong-hit expectation. Then a complex bucket-partition cryptograph index technology, which is used for nonequiprobable query, and a cryptograph query strategy are presented. Finally, information disclosure can be measured and eliminated using a k-anonymity based method. Experimental results demonstrate the improvement of our proposed method over the existing partition algorithms.