Bloom Filter Based Index for Query over Encrypted Character Strings in Database

It is important to construct more efficient index used for query over encrypted character strings in database. A few of approaches to deal with such issues have been worked out. In this paper, an bloom filter based index to support fuzzy query over encrypted character data is proposed on the principle of two-phase query. Firstly a triple is used to express a character string, then we use bloom filter compression algorithm on this triple to build encoded index, which will be saved in database as a numeric data. Optimal parameters are selected with the tradeoff between security and efficiency. In this way, the scheme minimizes not-match records by simple bit-and operation on the numeric index. Finally the improved query performance is proofed by experiment result.