Confidentiality-preserving query execution of fragmented outsourced data

Abstract

Ensuring confidentiality of outsourced data continues to be an area of active research in the field of privacy protection. Almost all existing privacy-preserving approaches to address this problem rely on heavyweight cryptographic techniques with a large computational overhead that makes inefficient on large databases. In this paper, we address this problem by improving on an existing approach based on a combination of fragmentation and encryption. We present a method for optimizing and executing queries over distributed fragments stored in different Cloud storage service providers. We then extend this approach by presenting a Private Information Retrieval (PIR) based query technique to enforce data confidentiality under a collaborative Cloud storage service providers model. © 2013 Springer-Verlag.