OT security: when a cyber incident stops a plant

Why OT is different

Operational environments have long lifecycles, systems that are hard to update and availability requirements that allow no downtime. IT security practices must be adapted: an aggressive scan or an unplanned update can itself cause an outage.

The reference: IEC 62443

The IEC 62443 family of standards organises industrial security into zones and conduits, with defined security levels and distinct responsibilities for asset owners, integrators and manufacturers. NIS2 and, for utilities, the Critical Entities Resilience Directive reinforce its adoption.

Priorities

1. Visibility: passive inventory of industrial assets and flows.
2. Segmentation between IT and OT networks, and within OT.
3. Controlled and logged remote access for maintenance contractors.
4. Continuous monitoring of industrial protocols.
5. Response plans shared between IT, OT and production teams.