Comprehensive Security Modelling for Evolving Cyber-Physical System Threats

Core Concepts

Cyber-physical systems (CPS) face dynamic, multi-layer, and multi-agent cybersecurity threats that require tailored security modelling approaches to ensure system resilience, safety, and reliability throughout the CPS lifecycle.

Abstract

This article provides a systematic review of the state-of-the-art research in CPS security modelling, encompassing both threat and attack modelling. The key findings are:

Threat modelling is commonly conducted in the early stages of CPS development, but evolving attacker tactics, techniques, and procedures (TTPs) over the system lifecycle can render these threat models outdated and irrelevant.

Existing security models predominantly focus on IT systems and do not adequately consider the unique complexities and multi-dimensional characteristics of real-world CPS attacks.

There is ambiguity in the literature regarding the definitions and relationship between threat modelling and attack modelling. A unified security modelling framework that integrates threat modelling, attack modelling, and security monitoring is proposed to enhance the cyber resilience of CPS.

The literature does not differentiate between cybersecurity breaches in IT systems versus CPS, where incidents can result in complex failure modes and consequences in both cyber and physical domains. A consequence-driven and cyber-informed approach to CPS security modelling is vital.

Research gaps include the need to better incorporate real-world cybersecurity intrusions and threat intelligence to inform and enhance security modelling throughout the CPS lifecycle, as well as the exploration of self-healing techniques to bolster CPS resilience against sophisticated adversaries.

Stats

"CPS find themselves at the intersection of digital technology and engineering, and consequently become a high-value target of cybersecurity threat actors."
"Prominent cybersecurity attacks on Cyber-Physical Systems (CPS) have brought attention to the vulnerability of these systems, and the soft underbelly of critical infrastructure reliant on CPS."
"Unlike IT systems, cybersecurity incidents in CPS can result in complex failure modes, as well as consequences in both cyber and physical domains."

Quotes

"Security modelling for CPS is an important mechanism to systematically identify and assess vulnerabilities, threats, and risks throughout system lifecycles, and to ultimately ensure system resilience, safety, and reliability."
"Existing cybersecurity frameworks like the NIST Cybersecurity Framework and international standards like IEC 62443-4-1:2018 offer valuable guidance for securing CPS. However, the dynamic nature and design constraints of CPS require a tailored approach, combining continual assessment and adaptation of physical measures, cybersecurity practices, as well as risk mitigation controls."
"There is ambiguity in the literature regarding the definitions and relationship between threat modelling and attack modelling."

Key Insights Distilled From

Security Modelling for Cyber-Physical Systems

by Shaofei Huan... at arxiv.org 04-12-2024

https://arxiv.org/pdf/2404.07527.pdf

Deeper Inquiries

How can real-world cybersecurity intrusions and threat intelligence be effectively incorporated to inform and enhance security modelling throughout the CPS lifecycle?

Incorporating real-world cybersecurity intrusions and threat intelligence into security modelling for CPS is crucial for staying ahead of evolving threats. One effective approach is to establish a feedback loop between incident response teams, threat intelligence analysts, and security modelers. By analyzing past intrusions and threat intelligence data, security modelers can identify patterns, tactics, techniques, and procedures used by attackers. This information can then be used to update and refine threat and attack models to better reflect current and emerging threats.
Furthermore, conducting regular red team exercises based on real-world scenarios can provide valuable insights into the effectiveness of existing security measures and the resilience of the CPS infrastructure. These exercises can help identify gaps in security controls, test incident response procedures, and validate the assumptions made in security models.
Continuous monitoring of the CPS environment for anomalous behavior and indicators of compromise can also provide valuable data for enhancing security models. By integrating real-time threat intelligence feeds and security monitoring tools, security modelers can proactively identify and respond to potential threats before they escalate into full-blown cyber incidents.

How can self-healing techniques be leveraged to bolster CPS resilience against sophisticated adversaries and threats, and what are the potential synergies with the proposed unified security modelling framework?

Self-healing techniques in CPS can play a critical role in bolstering resilience against sophisticated adversaries and threats. These techniques involve the automatic detection and mitigation of security incidents, such as isolating compromised components, restoring system functionality, and applying patches or updates to address vulnerabilities.
One way to leverage self-healing techniques is to integrate them with the proposed unified security modelling framework. By incorporating self-healing capabilities into the security architecture of CPS, organizations can automate responses to security incidents based on predefined rules and policies. This proactive approach can help mitigate the impact of cyber attacks and reduce the time to detect and respond to security breaches.
Additionally, self-healing techniques can complement the threat and attack modelling components of the security framework by providing real-time feedback on the effectiveness of security controls and incident response procedures. By continuously monitoring and adapting to changing threat landscapes, self-healing mechanisms can enhance the overall resilience of CPS infrastructure and improve the system's ability to withstand cyber attacks.
The synergies between self-healing techniques and the unified security modelling framework lie in their shared goal of enhancing the cybersecurity posture of CPS. By integrating self-healing capabilities with threat and attack modelling, organizations can create a more dynamic and adaptive security environment that can respond effectively to evolving threats and adversarial tactics.

What are the potential counter-arguments to the consequence-driven and cyber-informed approach proposed for CPS security modelling, and how can they be addressed?

One potential counter-argument to the consequence-driven and cyber-informed approach for CPS security modelling is the complexity and resource-intensive nature of implementing such a framework. Some organizations may argue that the cost and effort required to continuously monitor and analyze cyber threats, as well as the potential impact on system performance, outweigh the benefits of a proactive security approach.
To address this counter-argument, it is essential to emphasize the long-term benefits of investing in a robust security framework for CPS. By highlighting the potential cost savings from preventing cyber incidents, minimizing downtime, and safeguarding critical infrastructure, organizations can justify the upfront investment in implementing a consequence-driven and cyber-informed approach.
Another counter-argument could be the lack of standardization and best practices in consequence-driven security modelling for CPS. Critics may argue that without clear guidelines and industry standards, organizations may struggle to effectively implement and maintain such a framework.
To counter this argument, industry collaboration and knowledge sharing can help establish common practices and guidelines for consequence-driven security modelling in CPS. By engaging with industry experts, regulatory bodies, and standards organizations, organizations can work towards developing a unified approach to cybersecurity that addresses the unique challenges of CPS environments.
Overall, addressing potential counter-arguments to the consequence-driven and cyber-informed approach involves demonstrating the value, feasibility, and long-term benefits of implementing a proactive security framework for CPS. By emphasizing the importance of resilience, safety, and reliability in critical infrastructure, organizations can make a compelling case for adopting a comprehensive security strategy that aligns with the proposed approach.