Invalidating Policies using Structural Information

Florian Kammüller¹⁺ and Christian W. Probst²

¹Middlesex University, UK
f.kammueller@mdx.ac.uk
²Technical University of Denmark, Denmark
cwpr@dtu.dk

Abstract

Insider threats are a major threat to many organisations. Even worse, insider attacks are usually hard to detect, especially if an attack is based on actions that the attacker has the right to perform. In this paper we present a step towards detecting the risk for this kind of attacks by invalidating policies using structural information of the organisational model. Based on this structural information and a description of the organisation’s policies, our approach invalidates the policies and identifies exemplary sequences of actions that lead to a violation of the policy in question. Based on these examples, the organisation can identify real attack vectors that might result in an insider attack. This information can be used to refine access control systems or policies. We provide case studies showing how mechanical verification tools, i.e. modelchecking with MCMAS and interactive theorem proving in Isabelle/HOL, can be applied to support the invalidation and thereby the identification of the attack vectors.

Keywords: organisational structure, policies, formal methods

+: Corresponding author: Florian Kammüller

Department of Computer Science, Middlesex University, Town Hall, The Borroughs NW4 4BT

London, UK, Tel: +442084114930

Journal of Wireless Mobile Networks, Ubiquitous Computing, and Dependable Applications (JoWUA),

Vol. 5, No. 2, pp. 59-79, June 2014 [pdf]