What Is Industrial Control Systems (ICS) Security?

What are industrial control systems (ICS)?

An industrial control system (ICS) is a set of systems, equipment, and devices used to monitor, control, and automate industrial processes. These systems are critical in manufacturing, energy, water treatment, and other infrastructure. They enable safe and efficient operation of processes.
There are several types of ICS systems, the most common of which are supervisory control and data acquisition (SCADA) and distributed control systems (DCS). Oftentimes, actual ICS implementations are a hybrid of SCADA and DCS.

What is ICS security and why is ICS security important?

ICS security refers to the strategies, technologies, and practices used to protect industrial control systems from cyber threats, unauthorized access, and other security risks. Given ICSs are often responsible for critical processes in manufacturing and infrastructure, their security is critical to ensure safety, reliability, and continuity.

How does ICS security work?

ICS security works to reduce risks and impacts of downtime to critical operations. It protects components from malware, ransomware, phishing, and other cyberthreats. To ensure operational integrity, it prevents unauthorized changes to configurations or commands, maintaining process functionality. Secure data communications safeguard data integrity, preventing interception or tampering of control signals between devices and components.

Common ICS security challenges

External threats and targeted attacks

External threats in ICS security refers to risks originating outside the organization or industrial environment that can compromise the confidentiality, integrity, or availability of ICS components. Common external threats include malware and ransomware, phishing attacks, nation-state actors, hacktivists, insider threats with external influence, supply chain attacks, and more.

Internal threats

Internal threats in ICS security refers to risks posed by individuals or processes within the organization or facility that can compromise security, safety, or functionality of the system. These threats can be intentional or unintentional and are significant because insiders often have direct access to critical systems and privileged information. Common examples include malicious insiders, errors caused by well-meaning employees, or third-party risks from vendors, suppliers, or even maintenance personnel.

Human error

Human error refers to mistakes or oversights by employees, operators, or other individuals that compromise safety, security, or functionality of ICS environments. Examples include configuration errors, improper patching, neglecting security protocols, unauthorized device usage, and/or data entry errors.

High availability requirements

ICS systems need to remain operational and accessible, even in the presence of hardware failures, software issues, cyberattacks, or other disruptions. To have high availability, ICS systems need to plan for redundancy, failover mechanisms, disaster recovery, patch management without downtime, cyber resilience, monitoring and alerts, secure communication, and more.

Insecure proprietary protocols

Insecure proprietary protocols in ICS security are common. Legacy devices and machines—all with their own protocols—lack modern security features like encryption, authentication, and integrity verification. These protocols were often designed for reliability and real-time performance in isolated environments; however, never designed for security in connected or internet-facing environments.

Focus on detection over prevention

Oftentimes, ICS security is configured to detect attacks rather than control them. This is a result of ICS requiring high availability, as the possibility of lawful operations being prevented is a significant worry.

How does integrating IT and OT help achieve ICS security?

Integrating information technology (IT) and operational technology (OT) achieves ICS security by creating a unified security approach that leverages the strengths of both people, processes, and systems. This approach enables better threat detection, response, and overall protection of critical processes by bridging the knowledge gap between the teams, establishing joint governance, and implementing compatible security technologies that work across both environments.

ICS security best practices

Best practices for ICS security ensure protection of critical infrastructure and operations from cyberthreats, human error, and operational disruptions. These practices focus on security operational technology (OT) and information technology (IT) to minimize vulnerabilities and ensure resilient operations.

<span style="background-color: #f3f3f3; color: #323b42;">Best practices for ICS security ensure protection of critical infrastructure and operations from cyberthreats, human error, and operational disruptions. These practices focus on security operational technology (OT) and information technology (IT) to minimize vulnerabilities and ensure resilient operations.</span>

Network segmentation

Isolating ICS from IT networks physically and logically can help limit exposure to external threats. Oftentimes, this is achieved using demilitarized zones (DMZs) to control traffic flow between ICS and external networks.

Access control and user authentication

Best practice is to follow the principle of least privilege, meaning use access should be limited to the minimum required for the role of the user, ensuring operators only have access to what they need to perform their tasks.

Secure remote access

Limiting and securing remote access is considered a best practice for ICS security. This includes using VPNs with encryption, limiting remote access to only when necessary, and also monitoring remote sessions.

Regular patch management

Timely deployment of patches ensures software and hardware are updated to fix vulnerabilities and security flaws. Firmware on ICS devices, including controllers, sensors, and other field devices is strongly recommended.

Secure communication protocols

Leveraging secure protocols for data transmission within ICS networks protects against eavesdropping and tampering. Where possible, transition to secure versions of legacy protocols (e.g., OPC UA, MQTT) that offer encryption and/or authentication.

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ICS security frequently asked questions (FAQs)

What Is ICS Protection?

Industrial control systems (ICS) protection refers to the security measures, practices, and technologies aimed at safeguarding ICS from cyberthreats, physical threats, human error, and other vulnerabilities. ICS systems are used to control critical infrastructure and manufacturing operations, and protecting them is critical to ensuring safety, reliability, and continuity of operations.

What Is the Difference Between IT and ICS Security Systems?

ICS security systems focus on protecting the systems used to control and monitor industrial processes. The goal of these systems is to ensure availability, reliability, and safety—with emphasis on maintaining continuous operation. IT security focuses on protecting traditional information systems and business technology, such as computers, servers, networks, and databases, for business operations and communications.

What’s the Difference Between ICS and SCADA?

ICS and SCADA are both systems used to manage and control industrial processes, but they refer to different concepts within the broader field of industrial automation. ICS refers to the entire ecosystem of control and monitoring systems that manage operations. ICS covers everything from control logic (like PLCs) to the user interface (like HMIs) and communications used to manage the processes. SCADA is a specific type of control system within the category of ICS. It is specifically designed for remote monitoring and control, providing a centralized platform to control systems. SCADA systems typically include a user interface (HMI), database, and software used for process control and data analysis.