IT/OT Convergence and Critical Infrastructure Protection: PKI for PLCs and SBOM Transparency

For years, OT networks were separate and “air-gapped” from IT. But the push for real-time data, predictive maintenance, and efficiency has converged the two worlds. IT/OT convergence creates business value but also sharply widens the attack surface.

New Convergence Risks

• IT malware can now leak into the control network.
• Legacy OT devices never designed for connectivity become exposed.
• The software and hardware supply chain becomes a serious attack vector.

Device Identity with PKI

In a converged architecture, trust cannot be based on network location. Every device — from a PLC to an industrial gateway — must have a unique cryptographic identity and authenticate via PKI before communicating. This makes device spoofing and unauthorized commands to the process much harder.

Supply-Chain Transparency with SBOM

Many major incidents begin with a vulnerable component deep in the supply chain. A Software Bill of Materials (SBOM) is a machine-readable inventory of all components and libraries in a product. With an SBOM, when a new vulnerability is announced you know within minutes which devices are affected — not weeks.

Secure by Design

Instead of endless patching, vendors and operators are moving to secure-by-design principles: eliminating default passwords, encryption by default, least privilege, and signed updates. This shifts the security burden from the end user to the manufacturer.

A Practical Protection Framework

1. Build and maintain an SBOM for all critical assets.
2. Deploy PKI and device identity across the OT fleet.
3. Continuously monitor network behavior with AI-based anomaly detection.
4. Maintain an OT-specific incident response plan with regular drills.
5. Align with IEC 62443 and the relevant sector's NIS2 requirements.