ISA/IEC 62443 Consulting
Secure your industrial automation and control systems against cyber threats with the leading standard for OT security.
Talk to an OT specialistOperational Technology
OT Cyber Security Services
Practical OT cyber security for industrial operators who need safety, availability and assurance built around their existing engineering culture.
OT / ICS practice
Safe for live plant. Built by practitioners.
ICS / SCADAPurdue ModelIEC 62443CNI
Frameworks
Risk Management Frameworks
A structured set of approaches for identifying, assessing and managing cyber risk in operational technology environments.
IEC 61511 Consulting
Strengthen functional safety across your process industry systems with expert Safety Instrumented System guidance.
Talk to an OT specialistNIST Consulting
Build resilience and close capability gaps using the US's leading cyber security standards body.
Talk to an OT specialistNICE Consulting
Build a capable, well-trained cyber security workforce using the NICE Cybersecurity Workforce Framework.
Talk to an OT specialistNIS2 Consulting
Meet the EU's strengthened Network and Information Security Directive with confidence.
Talk to an OT specialistCyber Essentials & Cyber Essentials Plus
Achieve the UK Government-backed baseline cyber security certification, with full support through to Plus-level verification.
Talk to an OT specialistNCSC Cyber Assessment Framework (CAF)
Navigate the National Cyber Security Centre's structured framework for managing cyber risk and building resilience.
Talk to an OT specialistDefinition
What Is OT Cyber Security?
Operational technology is the hardware and software that monitors and controls physical equipment. OT cyber security is the discipline of keeping that equipment safe, available and trustworthy when it is exposed to network-borne threats.
An OT estate typically includes programmable logic controllers (PLCs), remote terminal units (RTUs), distributed control systems, SCADA servers, human-machine interfaces, historians, engineering workstations and safety instrumented systems. Many were commissioned long before network exposure was a design consideration, and they were never intended to be reachable from a corporate network or the internet.
As plants converge with enterprise IT for reporting, predictive maintenance and remote vendor support, that isolation disappears. The result is a large installed base of long-lived, unauthenticated, difficult-to-patch assets sitting a small number of hops away from a phishing email - which is why OT cyber security is treated as a distinct discipline rather than an extension of IT security.
The consequence of failure is also different in kind. A compromised OT environment can mean loss of view or loss of control over a physical process: unplanned shutdown, damaged equipment, environmental release, or interruption to a service that a region depends on. Safety, therefore, sits above confidentiality in every OT security decision.
IT vs OT
How OT Security Differs From IT Security
The controls are recognisable, but the priorities, constraints and consequences are not. This is the comparison we use with boards and engineering teams.
| Dimension | IT security | OT cyber security |
|---|---|---|
| Primary objective | Protect data confidentiality | Protect safety and process availability |
| Asset lifespan | 3 to 5 years | 15 to 30 years, often longer |
| Patching | Routine, often automated | Tied to plant outage windows and vendor approval |
| Protocols | TCP/IP, HTTPS, authenticated by design | Modbus, DNP3, PROFINET, OPC - largely unauthenticated |
| Impact of failure | Data loss, financial and reputational harm | Physical harm, environmental release, loss of supply |
| Active scanning | Standard practice | Can crash controllers - passive methods preferred |
Our Capability
How Siker Secures Operational Technology
Consultancy and training delivered by practitioners who work in live industrial environments.
Asset discovery and network baselining
Passive identification of controllers, engineering workstations, historians and remote access paths, mapped against the Purdue Model so you know what is in each zone before anything changes.
Risk assessment to IEC 62443
Zone and conduit definition, target security levels and a prioritised remediation plan written for engineering and security teams to share.
Segmentation and secure remote access
Design and implementation support for IT/OT boundaries, DMZ architecture, jump hosts and vendor access that survives an audit.
OT-aware monitoring and response
Detection use cases built for control system protocols, plus incident response playbooks that account for safety systems and plant operations.
Governance, compliance and vCISO
Board briefings, policy and standards work, and fractional leadership for organisations building an OT security function from a standing start.
Training and capability building
Instructor-led ICS and OT courses plus eLearning through the Siker Academy, so engineers and analysts share one language for OT risk.
Next step
Start With Visibility
Tell us what you run and where you are in your programme, and we will tell you honestly what the first phase should be.
Questions
OT Cyber Security FAQs
What is OT cyber security?
OT cyber security is the practice of protecting operational technology - the hardware and software that monitors and controls physical processes such as pumps, valves, turbines, conveyors and switchgear. It covers industrial control systems (ICS), SCADA, PLCs, RTUs, safety instrumented systems and the networks that connect them. Its primary objective is to keep the physical process safe and available, not simply to protect data.
What does OT stand for in cyber security?
OT stands for operational technology. It is used to distinguish process control and industrial automation systems from IT (information technology), which handles business data and enterprise applications.
How is OT security different from IT security?
IT security usually prioritises confidentiality, then integrity, then availability. OT reverses that order: safety and availability come first, because taking a controller offline can stop production or create a hazard. OT assets also have far longer lifespans, often cannot be patched on demand, and frequently run protocols such as Modbus, DNP3, PROFINET and OPC that were designed without authentication.
What is the Purdue Model?
The Purdue Enterprise Reference Architecture is a layered model (Levels 0 to 5) used to segment industrial environments, from field instrumentation at Level 0 up to enterprise IT at Level 5, with a demilitarised zone between the plant and the business network. It is the most widely used reference point for OT network segmentation and conduit design.
Which standards apply to OT cyber security?
IEC 62443 is the core international series for industrial automation and control system security, covering zones and conduits, security levels and supplier requirements. Depending on sector and geography, operators may also work to NIS2, NIS Regulations and the NCSC CAF in the UK, NERC CIP in North America, and regional frameworks such as Saudi OTCC.
Where should an OT security programme start?
With visibility. Most programmes begin with a passive asset inventory and network baseline, because you cannot segment, patch or monitor what you have not identified. Risk assessment, zone and conduit design, secure remote access and OT-aware monitoring follow from that inventory.