A Density-Aware Data Encryption Scheme with Query Auditing Index for Secure Mobile Services

Abstract

In database outsourcing, because a service provider might be untrusted or compromised, two issues of data security emerge: data confidentiality and data integrity. Motivated by these issues, we propose a density-aware data encryption scheme and a query processing algorithm with query result auditing for secure mobile services. To guarantee the data confidentiality, our density-aware data encryption scheme utilizes a grid index to transform the original data space into a bitmap signature. In addition, to reduce the transmission overhead of verification data, we propose a query result authentication index that stores an encrypted signature for each anchor, which is the concatenated hash digest of clustered data. Through performance evaluation, we show that the proposed scheme guarantees the high level of privacy preservation to users while providing better query processing performance, compared with the state-of-the-art schemes.