OT Security in Ireland: Two Forces Converging on Critical Infrastructure

For organisations operating operational technology and critical national infrastructure in Ireland, two pressures are arriving at the same time. The first is regulatory. The second is technical. Both are forcing organisations to rethink whether their OT environments are designed not just to prevent attacks, but to contain them and maintain operations when prevention fails.

For organisations responsible for keeping essential services and industrial processes running, that shift is becoming increasingly important. Cybersecurity is no longer just about keeping attackers out. It is about limiting the impact when they get in.

The regulatory pressure is personal

NIS2 has shifted the cybersecurity conversation in a way that previous directives did not. The directive places greater responsibility on CEOs and governing bodies to oversee cybersecurity risk management, approve the measures taken, and take responsibility for the organisation's cybersecurity posture.

Ireland has not yet transposed NIS2 into national law, and the European Commission has already taken action over the delay. That legislative gap has done nothing to remove the practical pressure. Banks, utilities, manufacturers and other organisations across NIS2 and DORA-regulated supply chains are already asking partners and suppliers for evidence of cybersecurity controls. Insurers are increasingly asking for evidence of security measures before providing cover.

The compliance pressure is therefore arriving through commercial channels well ahead of full national implementation.

For many organisations, the IT environment can answer these questions. There are controls, logs, audit trails and evidence that those controls are operating. The OT environment is a different proposition entirely.

OT was not built for this conversation

Operational technology networks were designed around process continuity and uptime. Flat architectures, minimal segmentation, devices running for decades without patching, and proprietary protocols that predate modern security controls were acceptable trade-offs when OT environments were largely isolated from IT networks and the wider internet.

That isolation has been eroding for years.

IT/OT convergence, IIoT adoption and remote access requirements have connected industrial environments to the broader enterprise. The security assumptions those environments were built on no longer hold, but the underlying architectures have often not changed to reflect that reality.

When a supply chain partner or an insurer asks whether an organisation can demonstrate segmentation between IT and OT, or what visibility it has over east-west traffic inside its industrial environment, the honest answer for many organisations is that the controls exist in principle, but the evidence does not.

A perimeter firewall can protect the boundary without providing visibility into what is happening inside a flat OT network. A policy document describes intent, not capability.

NIS2 is not based on the assumption that organisations can prevent every attack. It places greater emphasis on effective cybersecurity risk management, incident handling and resilience, including the ability to maintain or restore operations when an incident occurs.

For senior leadership accountable for that resilience, the distinction matters enormously.

A shutdown-and-recover posture may have been acceptable in the past. The more important question now is whether an organisation can contain a breach and maintain a minimum viable set of operations while incident response works to resolve it.

That is a structural capability. It requires segmentation granular enough to isolate compromised areas of the OT network without taking down production, enforced across devices that were never designed to support modern security controls.

AI is compressing the timeline

While the regulatory pressure builds, the threat to OT environments is accelerating in parallel.

AI does not need to invent a completely new way into an OT environment to create a problem. It can make existing attack paths faster to discover and exploit.

Reconnaissance, vulnerability discovery and lateral movement can increasingly be automated or accelerated, compressing the time defenders have to identify and contain an intrusion. In a flat OT environment, that speed can turn a relatively small initial compromise into a major operational incident far faster than traditional response processes were designed to handle.

At the same time, increasingly sophisticated ICS/SCADA-focused malware is expanding the range of techniques organisations may need to defend against. The combination of flat architectures and faster, more automated attacks is making OT security an increasingly urgent resilience issue.

The Cloud Security Alliance has published a strategic briefing, vetted by 250 CISOs, setting out eleven priority actions for building an AI-ready security programme. Gartner's OT/CPS analyst has also highlighted asset discovery, traffic analysis and segmentation as fundamental controls for organisations managing cyber-physical systems.

Across these recommendations, the same theme emerges: prevention alone is not enough.

Organisations need to build for containment and resilience, the ability to limit the blast radius of a breach and keep critical operations running while the incident is managed.

For OT environments, this is a particularly difficult problem. The flat architectures and unmanaged devices that define many industrial networks offer very little resistance once an attacker has gained a foothold. Without granular segmentation in place before an attack begins, there may be no effective mechanism to stop lateral movement from spreading across the operational network.

The two forces meet in the same place

The regulatory question and the technical question ultimately converge on the same requirement.

NIS2 asks organisations to take cybersecurity risk and resilience seriously at senior leadership level. AI-driven threats are increasing the speed at which weaknesses can be discovered and exploited.

In both cases, the answer depends on whether the organisation has built its OT environment for breach readiness, with segmentation, visibility and containment in place before the incident occurs.

For Irish organisations operating in essential and important sectors, this is becoming an immediate concern. Supply chain security assessments are already asking difficult questions. Accountability for cybersecurity is increasing across Europe. AI-accelerated threats to industrial networks are developing rapidly.

The window between recognising the problem and being assessed on the organisation's ability to manage it is closing.

Building for breach readiness

The answer is not simply adding another layer of prevention around the perimeter.

OT environments need to be designed with the assumption that a determined attacker may eventually gain access. The priority then becomes limiting what that attacker can reach.

Granular microsegmentation can help organisations isolate workloads, devices and operational zones without requiring production environments to be taken offline. It can provide visibility into traffic moving within the OT environment and enforce policies designed to prevent compromised devices from communicating beyond what is required.

This is particularly important in environments containing legacy and unmanaged devices that cannot run security agents.

The objective is not to make every OT environment perfectly secure. It is to make a breach containable.

That is the difference between a security strategy built around prevention and one built around resilience.

The OT Forum: From Compliance to Resilience

These two forces, regulatory accountability and accelerating technical threats, are the focus of Renaissance and ColorTokens' upcoming OT Forum.

The two-session virtual series explores the challenge from both sides: first, the regulatory and commercial pressure created by NIS2; and second, the emerging threat posed by increasingly automated and AI-accelerated attacks.

Session 1 | Tuesday 20th October, 11am

NIS2: The OT Problem Nobody Is Solving

What NIS2 accountability means for organisations running OT and critical infrastructure, and what breach readiness looks like when operations cannot afford to stop.

Session 2 | Tuesday 24th November, 11am

When AI Finds the Gaps in Your OT Network

How AI-driven attacks are changing the speed and scale of threats against industrial environments, and the practical controls that can contain an attack before operations are affected.

Both sessions are hosted by Adrian Young, Regional Vice President, EMEA, ColorTokens, and David Keating, Sales Director, Renaissance.

Why ColorTokens?

The case for microsegmentation is also reflected in the wider security market. ColorTokens is rated a Leader in The Forrester Wave™: Microsegmentation Solutions, Q3 2026, recognising its position in the microsegmentation market and the role of the technology in strengthening segmentation and breach containment.

For organisations operating OT and critical infrastructure, the objective is clear: limit lateral movement, contain compromise and maintain critical operations when prevention fails.

Register for the OT Forum

If your organisation operates OT or critical infrastructure, the question is no longer simply whether your environment can prevent an attack.

It is whether it can contain one without stopping the operation.

The OT Forum: From Compliance to Resilience explores that challenge across two connected sessions, from the accountability created by NIS2 to the accelerating threat posed by AI.

Join Renaissance and ColorTokens this autumn to understand the risks, the resilience challenge and the practical controls that can help keep critical operations running through a breach.

Register for the OT Forum here - https://renaissance.renaissance.ie/c/458653/