Model-Based Evaluation of the Resilience of Critical Infrastructures Under Cyber Attacks

Abstract

Abstract. In this paper we report recent results on modelling the impact of cyber-attacks on the resilience of complex industrial systems. We use a hybrid model of the system under study in which the accidental failures and the malicious behaviour of the Adversary are modelled stochastically, while the consequences of failures and attacks are modelled in detail using deterministic models. This modelling approach is demonstrated on a complex case study -a reference power transmission network (NORDIC 32), enhanced with a detailed model of the computer and communication network used for monitoring, protection and control compliant with the international standard IEC 61850. We studied the resilience of the modelled system under different scenarios: i) a base-line scenario in which the modelled system operates in the presence of accidental failures without cyber-attacks; ii) several different scenarios of cyberattacks. We discuss the usefulness of the modelling approach, of the findings, and outline directions for further work.

Using Structured Assurance Case Approach to Analyse Security and Reliability of Critical Infrastructures

“…In the later case, a model of Adversary is added in which the Adversary is tightly coupled with the assets. Further details about the case study and the various modeling assumptions can be found in papers [13,14].…”

“…For our study, we analysed the effect of a single type of attack on system behavior: a cyber-attack via the firewall of a sub-station. The detailed model of Adversary and attack scenarios we developed are outside the scope of this paper and are described in recent publications [13], [16]. The justification of the models are performed in the side-warrant of the Concretion block.…”

“…The length of a simulation run was selected be the equivalent of 10 years of operation. The details of our evaluation can be found in papers [13,14]. Evidence Incorporation blocks are used to feed the results from PIA into the assurance case.…”

Stochastic Modeling of Safety and Security of the e-Motor, an ASIL-D Device

“…A small number of parameters, characterizing the transitions between the states (that capture the possible multi-step paths of successful attacks) should allow a modeler to capture various scenarios and defense policies. This approach has been tried in the past [6].…”