As industry adopts more automation and connectivity, the risk of cyberattack grows with it, and operational technology (OT) cybersecurity becomes essential to protecting the services and infrastructure everyone depends on. Bringing OT and information technology (IT) together improves efficiency and productivity, and it also creates complex security problems that need careful solutions.
This article covers the basics of OT cybersecurity, the main threats to industrial operations, the strategies that make them more resilient, the laws and frameworks that set compliance obligations, and practical steps for building a secure OT framework.
What is OT cybersecurity?
Operational technology is the hardware and software that monitors, controls and directly interacts with physical devices and processes. It runs manufacturing, power distribution and transport systems. That sets it apart from IT, which is mostly about data and computing in business settings.
Where OT is used
OT is used throughout manufacturing, utilities and transport. It keeps factories running, the power supply steady and public transport on schedule. It includes industrial control systems (ICS), supervisory control and data acquisition (SCADA) systems and programmable logic controllers (PLCs), all designed to run continuously and reliably, often in harsh conditions. OT systems are built to last for many years without interruption, unlike IT systems, which are updated and replaced frequently. That longevity leaves them exposed to cyber threats if they are not properly protected.
Why OT cybersecurity matters
Because OT systems provide critical services, they are a major target, and attacks on them have real-world consequences. An attack on a power grid could cause widespread blackouts. An attack on a water treatment plant could affect the water quality of an entire city. OT cybersecurity protects public health and safety as well as information.
The convergence of IT and OT has widened the attack surface. Organizations need OT systems that can withstand an incident, recover from it quickly and keep critical operations running during and after an attack. Effective OT security means close monitoring of network traffic to detect and respond to threats quickly, the right security technology, and strict compliance with regulatory standards, protecting against criminals and espionage alike.
As OT becomes more connected and more reliant on the internet, organizations must keep assessing and improving their OT security. That includes updating security procedures regularly, training employees and getting IT and OT teams to work together so every system is covered.
The main threats to OT
Attacks on OT can be direct or indirect, and each needs its own defenses.
Direct attacks
Direct attacks exploit vulnerabilities in the OT systems themselves: outdated software, weak access controls or other system-specific weaknesses that let an attacker in and give them control. The consequences can be severe, from disrupted critical infrastructure to damaged equipment and even injury to staff. These sophisticated attacks are often carried out by threat actors linked to hostile states, aiming for maximum disruption.
Indirect attacks
Indirect attacks start in connected IT systems and then pivot to the OT network. They often begin with malware or another technique that gets into an IT system. From there, the attacker moves laterally into the OT network, where they may take control of industrial processes or reach sensitive data. These attacks show how closely IT and OT are connected, and why security has to cover both.
A minor system failure or a compromised, non-critical piece of software can look harmless at first and then escalate into serious damage or data theft. A compromised data centre cooling system, for example, can cause lasting damage to equipment and long operational problems. Large organizations, especially those handling sensitive data such as government agencies and healthcare providers, should extend their security to these indirect targets to reduce the risk of intellectual property theft, privacy violations and reputational damage.
Both kinds of attack call for close monitoring, strong security procedures, effective detection and continuous improvement, with IT and OT teams working together.
Strategies for stronger OT cybersecurity
Network segmentation
Network segmentation divides a network into smaller, isolated segments, which limits how far an attack can spread and protects the most critical assets. Each segment gets security controls suited to its risk level and function, so sensitive systems get maximum protection while the access needed for smooth operations is kept.
For effective segmentation:
- Apply the principle of least privilege, so access is limited to the resources and functions each user needs.
- Divide networks into zones by function or criticality, with strong access controls between them.
- Separate OT networks from IT networks with firewalls and demilitarized zones (DMZs) that control the traffic between them.
Segmentation also improves performance, by preventing congestion and letting high-priority OT traffic flow freely. It makes compliance easier too, with a clear separation between data types and access levels that simplifies audits.
Segmentation only protects you if it holds under attack. A network penetration test of the IT side and the boundary into OT checks whether an attacker who compromises an office laptop could reach your control network. Testers work carefully, and inside agreed limits, around live industrial systems.
Security monitoring
Real-time monitoring and logging let you detect and respond to threats quickly by spotting anomalies and possible incidents. Monitoring built for OT, with anomaly detection and centralized logging, improves your ability to find threats.
Continuous monitoring can include:
- intrusion detection systems (IDS) designed for OT environments,
- passive network monitoring, such as network TAPs and deep packet inspection (DPI), which observe and analyze traffic without interfering with it,
- and active querying, which collects extra information from devices over the OT network for visibility beyond what passive monitoring provides.
Combining network monitoring with physical-layer monitoring detects physical changes to devices as well as cyber threats, which gives OT systems two layers of protection.
These strategies make OT systems more secure, more efficient and easier to keep compliant.
Regulatory and compliance frameworks for OT
Regulations and frameworks set the standards organizations must follow to secure critical infrastructure. Two of the most important are NIST SP 800-82 and the North American Electric Reliability Corporation Critical Infrastructure Protection (NERC CIP) standards.
NIST SP 800-82
NIST Special Publication 800-82 is dedicated to the security of OT systems. Its latest revision, SP 800-82r3, gives a full overview of OT, typical system layouts and the threats and vulnerabilities these environments face. It sets out recommended safeguards and countermeasures, and addresses OT’s particular requirements for performance, reliability and safety, from industrial control systems to physical access control.
NERC CIP standards
The NERC CIP standards regulate the security of the Bulk Electric System (BES) in North America. They require utility companies to meet a baseline of cybersecurity measures that protect the BES against cyberattacks and vandalism.
The standards require the identification of critical assets, risk analysis and policies for monitoring and managing access to those assets. They also require firewalls to block vulnerable ports and security monitoring tools. Compliance protects the reliability of North America’s electricity supply.
Both frameworks are revised from time to time as threats and technology change. Organizations that run OT need to keep up with those changes to stay compliant and protect their operations.
Building a secure OT framework
A secure OT framework depends on identity management and access control, so only authorized people can reach critical systems and information.
Identity management
Identity and access management (IAM) is central to OT security, and the tools and processes must be implemented correctly to deliver their benefits. A zero trust model, built on “never trust, always verify” and “assume breach,” complements IAM by authenticating and authorizing every user before they reach any resource. It suits OT environments, where safety and reliability come first. Read more in our guide to zero trust security.
IAM best practices:
- User authentication: confirm users are who they say they are. Multi-factor authentication (MFA) adds several forms of validation.
- Least privilege access: give users the minimum access they need. Just-in-time (JIT) access grants it only when needed.
- Role-based and attribute-based access control (RBAC and ABAC): automate granting and removing access as people’s roles change.
- Auditing and monitoring: run regular audits and collect logs centrally to keep IAM policies strong, stay compliant and spot breaches.
Access control
Effective access control prevents unauthorized access and protects the integrity of OT systems.
- Strong authentication and password policies: the first line of defence for OT devices and systems.
- Network access control (NAC): improves visibility of the network, identifies unauthorized devices and manages access efficiently, including creating VLANs and taking defensive action based on the group or role of a device or user.
- Temporary access: manage access for subcontractors and maintenance staff securely. NAC can grant controlled access that is quick to revoke.
- Continuous improvement: keep refining access controls as threats and the operating environment change.
Focusing on identity management and access control protects critical infrastructure from internal and external threats and keeps operations safe and reliable. IBM explains the main types of cyber threat.
Conclusion
OT cybersecurity is central to keeping industry running. OT controls physical processes, and the risks to it keep changing, so resilience takes several layers: network segmentation, real-time monitoring, compliance with regulatory frameworks, and a culture of continuous improvement.
As OT and IT continue to merge, industry needs a proactive approach to security, with teams working together and modern protective technology in place. Stay alert, keep your security practices current and make sure your workforce understands the risks, and your operational technology will stay safe and reliable.
Protect your operations
Krylo Security tests the IT networks, remote access and web applications that connect to your industrial environment, within safety limits agreed with your operations team. Talk to us about a penetration test.
FAQs
How can we improve security in operational technology environments?
- Map your network and analyze its connections.
- Monitor for suspicious activity, exposures and malware.
- Adopt a zero trust security framework.
- Use suitable remote access tools.
- Manage identity and access effectively.
What is operational technology cybersecurity?
Gartner defines OT security as the practices and technologies used to protect people, assets and information, monitor and control physical devices, processes and events, and manage changes of state in enterprise OT systems. It draws on a wide range of security technologies.
Why does OT cybersecurity matter?
It keeps industrial environments and critical infrastructure running, secure and safe, and protects them from threats and disruption.
What are some simple ways to strengthen cybersecurity?
- Use strong, complex passwords.
- Update all software regularly to close vulnerabilities.
- Think before you click on any suspicious link.
- Turn on multi-factor authentication.