Access Control for Data Integration in Presence of Data Dependencies

Abstract

Abstract. Defining access control policies in a data integration scenario is a challenging task. In such a scenario typically each source specifies its local access control policy and cannot anticipate data inferences that can arise when data is integrated at the mediator level. Inferences, e.g., using functional dependencies, can allow malicious users to obtain, at the mediator level, prohibited information by linking multiple queries and thus violating the local policies. In this paper, we propose a framework, i.e., a methodology and a set of algorithms, to prevent such violations. First, we use a graph-based approach to identify sets of queries, called violating transactions, and then we propose an approach to forbid the execution of those transactions by identifying additional access control rules that should be added to the mediator. We also state the complexity of the algorithms and discuss a set of experiments we conducted by using both real and synthetic datasets. Tests also confirm the complexity and upper bounds in worst-case scenarios of the proposed algorithms.

Secure data outsourcing in presence of the inference problem: issues and directions

“…Data outsourcing and the inference problem is a research field that researchers have begun to investigate few years ago (Biskup et al, 2011;de Mantaras & Saina, 2004;di Vimercati et al, 2014;Haddad et al, 2014;Sayah et al, 2015;Sellami et al, 2015;Turan et al, 2017Turan et al, , 2018. Inference leakage is recognized as a major barrier to cloud computing and other data outsourcing or Database-As-a-Service arrangements.…”

A Survey Study on the Inference Problem in Distributed Environment (S)

“…Inference control in data integration systems have been investigated in the last decade through the works in [12,17,18]. In such systems, a mediator is defined as a unique entry point to the distributed data sources.…”

“…Complying with source policies means that a prohibited access at the source level should be also prohibited at the global level. [12,17,18] have demonstrated that despite the generation of a global policy at the mediator level that synthesizes and enforces the back-end data sources policies, security breaches still possible via inference channel produced by semantic constraints. The problem is that the designer of the system cannot anticipates the inference channels that arise due to the dependencies that appear at the mediator level.…”

“…The first work attempting to control inference in data integration systems was introduced in [12]. The authors propose an incremental approach to prevent inference with functional dependencies.…”

“…The authors of [18] have inspired from [12] to propose an approach aiming to control inference in data integration systems. The proposed methodology resort to formal concept analysis as a formal framework to reason about authorization rules and functional dependencies as a source of inference.…”