Research and Implementation of Cache Optimized Query Privacy Protection for Spatio-Temporal Data Based on PGSRQ-PIR

Abstract In view of the high redundancy of the nearest node of the Spark based user privacy protection query algorithm CRIP-V, the caching optimization algorithm PCPIR-V-CA is proposed. PCPIR-V has two parallel strategies, row strategy and bit strategy. The bit strategy divides the row into smaller pieces and improves the efficiency while the grid division is to small. The cache optimized algorithm of PCPIR-V first clusters the CPIR data transforms the data into tuples and caches them in each cluster. Finally it calulates the result based on the cached tuples and data. It has about 20 percents improvement than PGSRQ-PIR.