Modelling DoS Attacks & Interoperability in the Smart Grid

Smart grids perform the crucial role of delivering electricity to millions of people and driving today’s industries. However, the integration of physical operational technology (OT) with IT systems introduces many security challenges. Denial-of-Service (DoS) is a well-known IT attack with a large potential for damage within the smart grid. Whilst DoS is relatively well-understood in IT networks, the unique characteristics and requirements of smart grids bring up new challenges. In this paper, we examine this relationship and propose the OT impact chain to capture possible sequences of events resulting from an IT-side DoS attack. We then apply epidemic principles to explore the same dynamics using the proposed S-A-C model

Exhaustive Sampling of Docking Poses Reveals Binding Hypotheses for Propafenone Type Inhibitors of P-Glycoprotein

Overexpression of the xenotoxin transporter P-glycoprotein (P-gp) represents one major reason for the development of multidrug resistance (MDR), leading to the failure of antibiotic and cancer therapies. Inhibitors of P-gp have thus been advocated as promising candidates for overcoming the problem of MDR. However, due to lack of a high-resolution structure the concrete mode of interaction of both substrates and inhibitors is still not known. Therefore, structure-based design studies have to rely on protein homology models. In order to identify binding hypotheses for propafenone-type P-gp inhibitors, five different propafenone derivatives with known structure-activity relationship (SAR) pattern were docked into homology models of the apo and the nucleotide-bound conformation of the transporter. To circumvent the uncertainty of scoring functions, we exhaustively sampled the pose space and analyzed the poses by combining information retrieved from SAR studies with common scaffold clustering. The results suggest propafenone binding at the transmembrane helices 5, 6, 7 and 8 in both models, with the amino acid residue Y307 playing a crucial role. The identified binding site in the non-energized state is overlapping with, but not identical to, known binding areas of cyclic P-gp inhibitors and verapamil. These findings support the idea of several small binding sites forming one large binding cavity. Furthermore, the binding hypotheses for both catalytic states were analyzed and showed only small differences in their protein-ligand interaction fingerprints, which indicates only small movements of the ligand during the catalytic cycle

Modelling smart grid IT-OT dependencies for DDoS impact propagation

The traditional power network has now evolved into the smart grid, where cyber technology enables automated control, greater efficiency, and improved stability. However, this integration of information technology exposes critical infrastructure to potential cyber-attacks. Furthermore, the interdependent nature of the grid’s composite information and operational technology networks means that vulnerability extends across interconnected devices and systems. Therefore, a DDoS (Distributed Denial-of-Service) attack, which is relatively easy to deploy but potentially highly disruptive, can be used strategically against the smart grid with particularly egregious results. In this paper, we take inspiration from epidemiological modelling to propose a compromise propagation model, alongside a behavioural DDoS model, to explore how dependencies between the grid’s networks might influence the scale and impact of DDoS attacks. We found that the internal connectedness of a network amplifies the received impact of failures in an external network on which it is dependent. Furthermore, testing showed that alongside attack force, attack duration influences recovery times, due to both the quantity of resources consumed and the time needed to accumulate recoveries. The models were validated against simulations conducted with cyber-security providers L7 Defense, showing our approach to be a viable companion or alternative to traditional graph-based dependency models