Secure data outsourcing in presence of the inference problem: A graph-based approach

Abstract

In light of the emergence of Database-as-a-Service paradigm, secure data outsourcing has become one of the crucial challenges which strongly imposes itself. In such a scenario, access control is considered as a major challenge. In fact, access control policies of the data owner must be preserved when data is moved to the cloud. Here, we address this problem by considering inference leakage that could be produced by exploiting functional dependencies. The proposed approach is based on vertical partitioning to produce a set of secure sub-schemas stored in separated partitions in the distributed system. Then, we extend this approach by presenting a secure query processing model to preserve access control policies when querying data from distributed partitions. The effectiveness of our algorithms is confirmed through observations from a variety of conducted experiments.