Securing Cyber-Physical Systems

Dec 27, 2024

Cyber-Physical Systems (CPS) integrate both physical and digital components, making their security unique and more complex. Unlike traditional IT systems, which rely on data processing and storage, CPS connect the digital world to the physical world through sensors, actuators, and other embedded devices. This creates new attack surfaces and challenges, making cyber-physical systems security absolutely critical today.

What are Cyber-Physical Systems(CPS)?

Used in various critical industries such as healthcare, logistics, finance and more, cyber-physical systems are platforms that connect the physical world with the cyber world. They integrate computing, control and networking with the physical environment. The physical processes are monitored and controlled by the “cyber” part of the CPS—computing algorithms—via a constant feedback loop fed by sensors and actuators. The subsystems under a CPS can also work independently.

Cyber-physical systems can be thought of as an improvement upon physical systems; as they improve any physical system’s operational efficiency, performance, safety and reliability. They enable humans to interact with machines seamlessly while playing a pivotal role in our modern society.

CPS Examples by Industry

Cyber-physical systems enable modern society to thrive. They are used in practically every area of our daily lives and have become indispensable for almost all operations.

Healthcare: Patient care and monitoring via medical devices, including guided surgeries with medical robotics.
Manufacturing: Real-time analytics, automation and data collection for improved production quality and efficiency.
Logistics & Automotive: Self-driving vehicles as well as advanced driver assistance systems, vehicle-to-vehicle communication systems and intelligent traffic management systems.
Military: Well-known technologies such as satellite communication and unmanned systems, along with autonomous surveillance systems, real-time data acquisition and edge computing.
Cybersecurity: Encrypted communication, real-time data monitoring and disarming, automated malware mitigation and more.
Agriculture: Irrigation, real-time soil health monitoring, automated farming processes for more efficiency in increasing production.
Utilities: IoT devices used in civil infrastructure, predictive maintenance features in smart grids and process automation for reduced risk and increased safety.

Difference Between CPS and IoT

Although sometimes confused as similar terms, CPS and IoT have a distinct difference: The human factor.

IoT (Internet of Things) refers to the technology that allows separate devices to be interconnected for real-time monitoring, data exchange and analysis, or remote control. IoT devices, by nature, can work autonomously—like a smart thermostat.

Cyber-physical systems, on the other hand, require human input—however minimal. For example, self-driving cars might drive on their own, but they still need to communicate with a human in case of unknown or challenging scenarios. CPS are intricate systems of interconnected software and hardware designed for advanced functionality.

IT/OT Convergence Effect on CPS Security

Historically, IT and OT operated in separate silos with distinct security protocols. IT systems were designed for rapid updates and agility, while OT systems were built for stability and uptime, often with minimal cybersecurity measures due to their isolation.

With the convergence of IT and OT, OT systems are now exposed to the same risks as IT environments—cyberattacks, data breaches, and malware. A compromise in an IT network can now easily infiltrate OT systems, threatening the integrity of critical infrastructure. This is why safeguarding CPS requires a unified security approach, ensuring that both domains work in tandem to protect against emerging threats and vulnerabilities.

Cyber-Physical Systems Security Challenges

One of the major security challenges lies in the vast array of interconnected devices within CPS ecosystems. Many of these devices—such as sensors, controllers, and embedded systems—were not originally designed with cybersecurity in mind, making them vulnerable to exploitation. Additionally, the real-time nature of CPS requires systems to remain functional and responsive, leaving limited room for error or downtime in the face of a cyberattack. Attackers targeting CPS can cause significant physical damage or disrupt essential services, leading to financial losses, data breaches, or even safety risks.

Another challenge is the need for continuous monitoring and protection. The dynamic nature of CPS environments, where devices frequently interact with each other, creates a constant need for up-to-date threat intelligence and rapid response. As CPS grows increasingly interconnected, securing them demands a holistic approach that encompasses both the cyber and physical components, making it critical for organizations to adopt Zero Trust cybersecurity solutions and protocols.

Best Cyber-Physical System Security Strategies

To effectively secure Cyber-Physical Systems (CPS), organizations must adopt a multi-layered, proactive security strategy that addresses both the cyber and physical components of these systems.

Unidirectional Gateways

On the subject of cyber-physical systems security, we believe unidirectional gateways are currently being recommended as a solution, as they are ideal for facilitating physical isolation between networks. Especially ideal for protecting critical infrastructure networks, unidirectional gateways also allow for real-time data tracking.

According to Gartner® “Unidirectional gateways allow one-way communication only, so organizations can securely connect CPS to external networks and cloud platforms without introducing the risk that these connections can be used by attackers.”

Network Segmentation & Physical Isolation

By separating IT networks from OT environments, organizations can contain potential breaches and prevent the lateral movement of attackers. This network segmentation, along with physically isolating private and open networks via data diodes, helps mitigate risks from both internal and external threats.

Access Control

Given that many CPSs rely on human operators for monitoring and intervention, controlling who has access to critical systems is paramount. This includes enforcing role-based access controls (RBAC) and multifactor authentication (MFA) to limit access to sensitive devices and data. Additionally, encryption should be applied to sensitive communications between CPS components to ensure data integrity and confidentiality.

Vulnerability Assessments

Many vulnerabilities in embedded systems and IoT devices go unaddressed because they are often not patched or updated regularly. By creating a routine for monitoring, testing, and patching these systems, organizations can significantly reduce their attack surface.