Privacy Preserving SQL Queries

Abstract

One of the most substantial ways to protect sensitive information is encryption of data. However, the cryptographic method brings in some problems such as inefficiency and malfunctioning, especially impossibility of arithmetic. The previous works in this area have been proved insecure or can provide only a few or several SQL queries. Actually, there is no scheme which can support secure all kinds of SQL queries and arithmetic. We propose a novel scheme to solve this problem. We do not encrypt every data itself but permute all the data within each attribute so that we can break the relation of the data and the owner. Accordingly, the proposed scheme guarantees intractability of re-identification for data-owners' privacy and at the same time enables the miner to get the information he wants.