Secure Remote Access to OT Assets: A 62443-Compliant Approach

Remote access is essential for maintenance and troubleshooting — and one of the top attack vectors in industrial networks. IEC 62443 outlines how to implement it safely through strong authentication, authorization, and network segmentation.

Why Traditional VPNs Are Not Enough

• They often grant full network access instead of limited zones.
• Credentials are shared between technicians and vendors.
• Sessions aren’t logged or recorded for audit.

IEC 62443 Best Practices

• Use a brokered access gateway or jump server between IT and OT networks.
• Authenticate users with MFA and unique credentials.
• Authorize access based on roles and time-limited tickets.
• Record sessions for accountability and traceability.
• Disconnect automatically after maintenance windows.

Network Architecture Example

A DMZ hosts the remote-access gateway. Vendors connect via secure VPN → jump host → specific PLC or HMI. No direct routing into control zones is allowed.

Case Example: Packaging OEM

After adopting a 62443-compliant remote access solution, a packaging company reduced vendor connection times by 40% and achieved full traceability for audits.

Related Articles

• IEC 62443 Without Jargon: Zones, Conduits, and Real Controls
• User Management in OT: MFA, Jump Hosts, and Least Privilege
• Writing a 62443-Compliant Supplier Spec: What to Include

Conclusion

Remote access doesn’t have to mean risk. A properly segmented, monitored, and time-bound connection strategy satisfies IEC 62443 and keeps maintenance fast, safe, and compliant.