Operational Technology (OT) security is gaining visibility as industry starts to understand the threat to its processes, so we thought we would post some ideas on best practice. OT systems are an essential part of modern industry, and their security is critical to prevent disruptions to operations, theft of sensitive information, damage to equipment or harm to people. We often seen situations where the basics have been overlooked despite mature cyber security programmes: here are some reminders on best practice for protecting OT systems:

1. Network mapping (physical arrangements) and connectivity analysis (data flow mapping): identify all devices and connections within the network to proactively identify potential vulnerabilities and develop effective security measures.
2. Conduct risk assessments: regularly evaluate potential risks to the OT environment to identify and mitigate vulnerabilities.
3. OT asset inventory management: keep an updated inventory of all assets and devices within the OT environment, including their functions, operating systems, criticality and software, to ensure that security measures cover all systems.
4. Implement a zero-trust framework: assume that all network traffic is potentially malicious and implement a zero-trust security model that requires continuous authentication and authorization to protect against unauthorized access where possible.
5. Identity and access management: implement strict identity and access management policies, including the use of multi-factor authentication and level-based access privileges wherever possible.
6. Security training: educate employees and involve third-party vendors in cybersecurity exercises to better understand eachothers’ strengths and weaknesses.
7. Implement network monitoring and alerting: even rudimentary systems deliver real benefit.
8. Reduce attack surface area: limit the number of network ports, protocols and applications in use, and connected to outside networks and services.
9. Implement a multi-layer defendable environment: deploy multiple layers of defense, including firewalls, intrusion detection systems and endpoint protection solutions, to detect malware and prevent it from entering and propagating through networks.
10. Segregation of IT and OT networks: implement segregation solutions to separate IT and OT networks to minimise the risk of a cyber-attack spreading across the entire organization.

By following these best practices, companies can protect their OT systems against cyber threats and ensure the smooth operation of their critical industrial processes. It may look complex, but it is essential, and increasing automation of security processes makes OT security both feasible and affordable.