Information Flow Analysis of Combined Simulink/Stateflow Models

Abstract

Simulink and Stateflow are widely-used industrial tools for the development of embedded systems, e.g. in the automotive domain. In modern automotive control systems, multiple components are typically interconnected, and, nowadays, also have a connection to the internet. This poses severe threats, as safety-critical components may be subject to remote attacks, which divert control or information flow from non-critical to safety-critical components. In this paper, we present a novel approach for the analysis of information flow in combined Simulink/Stateflow models. The key idea of our approach is that we analyze the information flow in a given model by computing an over-approximation of the control flow and deduce whether all control flow conditions on a given path combined permit information flow or not. With our approach, we safely rule out the existence of information flow on specific paths. Thus, it enables us to reason about non-interference and the compliance with security policies.