IEC 62443 for Beginners: What the OT Security Standard Actually Requires
IEC 62443 is the reference framework for industrial cybersecurity. Here is a plain-language map of its parts and how to start applying it.
· 2 min
OT security / EN
TOPIC HUB
OT security & resilience
Operational technology security starts with knowing what you have and what talks to what. These guides cover asset inventory, network zones and conduits (IEC 62443, the Purdue model), controlled remote access, backups you have actually restored, and the everyday risks that production teams meet first — removable media, ransomware, unmanaged switches.
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A suggested reading order
OT security / EN
The Purdue Model Explained: Designing IT/OT Network Zones That Actually Work
The Purdue reference model is the backbone of industrial network design. Here is how to map your plant to levels and where the DMZ belongs.
· 2 min
OT security / EN
OT Asset Inventory: The Unglamorous First Step to Industrial Security
You cannot protect what you cannot see. How to build and keep an asset inventory that security and maintenance can both use.
· 2 minRELATED TOOLS
Try what you read.
PDF RESOURCES
All resources Take it to the meeting.
PDF · 2 pages
A PLC backup is not complete until recovery is tested
Plan a restore drill that checks project files, licenses, hardware dependencies and operational acceptance.
PDF · 2 pages
Make vendor remote access a controlled work session
Document the purpose, approved route, time window and closeout evidence for a maintenance connection.
ALL ARTICLES
Open in the article list Every article on this topic
OT security / EN
IEC 62443 for Beginners: What the OT Security Standard Actually Requires
IEC 62443 is the reference framework for industrial cybersecurity. Here is a plain-language map of its parts and how to start applying it.
· 2 minOT security / EN
The Purdue Model Explained: Designing IT/OT Network Zones That Actually Work
The Purdue reference model is the backbone of industrial network design. Here is how to map your plant to levels and where the DMZ belongs.
· 2 min
OT security / EN
IPv4 subnet planning for OT networks: CIDR, VLANs and address plans
A practical method for sizing OT subnets: how CIDR maps to host counts, how to leave room to grow, how to align subnets with cells and zones and how to document the plan.
· 4 minOT security / EN
OT Asset Inventory: The Unglamorous First Step to Industrial Security
You cannot protect what you cannot see. How to build and keep an asset inventory that security and maintenance can both use.
· 2 min
OT security / EN
Build an OT asset inventory without disrupting production
Start with existing evidence, reconcile device ownership and make unknown assets actionable.
· 2 min
OT security / EN
Implementing Zero Trust Networking for OT and Industrial Control Systems
How to apply zero trust principles to OT networks without breaking production: start with visibility, segment by zone, broker remote access and verify continuously, within the limits of legacy devices.
· 3 min
OT security / EN
Beyond Firewalls: Building Cyber Resilience in Industrial Control Systems
Zero Trust is a starting point, not an end state. Real resilience in ICS environments requires detection, recovery, and graceful degradation — not just prevention.
· 3 min
OT security / EN
Secure Remote Access for Legacy Industrial Equipment
Patterns for giving vendors, integrators and remote engineers controlled access to PLCs and HMIs without exposing them to the internet: brokered sessions, multifactor authentication, time limits and recording.
· 3 min
OT security / EN
Make vendor remote access a controlled work session
Document the purpose, approved route, time window and closeout evidence for a maintenance connection.
· 2 min
OT security / EN
Cybersecurity Hardening for PLCs: Steps That Work Without Breaking Production
Hardening a controller is different from hardening a server. Practical, low-risk measures for PLCs and their networks.
· 2 min
OT security / EN
PLC Program Backup Best Practices: Protecting the Code That Runs Your Plant
The only copy of a machine's logic should never live on a single laptop. A practical backup strategy for PLC programs of any age.
· 2 minOT security / EN
A PLC backup is not complete until recovery is tested
Plan a restore drill that checks project files, licenses, hardware dependencies and operational acceptance.
· 2 min
OT security / EN
Ransomware and OT: Why Traditional Endpoint Protection Is Not Enough
The playbook that protects office PCs does not transfer to controllers. What ransomware actually does to OT and where the defenses belong.
· 2 min
OT security / EN
USB and Removable Media in Industrial Environments: Real Risk, Practical Policy
Removable media bypasses every network control you can build. How to manage USB use in OT with a clean station, port control and an audit trail, without crippling workflows.
· 2 min
OT security / EN
Logging and Audit Trails for OT Systems: What to Collect and Where to Keep It
OT logging is hard because devices log poorly and clocks drift. A practical baseline that satisfies both engineers and auditors.
· 2 min
OT security / EN
Firmware Update Management for Industrial Devices: Policy Over Panic
Unpatched devices are a risk; botched updates are a production outage. A process for firmware that balances both.
· 2 minOT security / EN
Managed vs Unmanaged Industrial Ethernet Switches: Choose by Risk, Not Price
Unmanaged switches are cheaper; managed switches are controllable. When the difference matters - and when it doesn't.
· 2 min
Industrial protocols / EN
OPC UA security basics: modes, policies and certificate trust
What Sign and SignAndEncrypt actually change, which security policies to avoid, how application certificates and trust lists work, and the connection errors you will meet first.
· 3 min
OT security / EN
SCADA Redundancy and Failover: Designing for Availability, Not Magic
Redundant SCADA systems fail in interesting ways. What the standard topologies are and how to test the one you buy.
· 2 minCOMMON QUESTIONS
Short answers.
Where should I start with OT security?
With a passive asset inventory: document which devices exist, which software versions they run and who owns them. Then address network zones and remote access.
Do these guides replace a security assessment?
No. They are informational; a site-specific risk assessment and conformity with the relevant standards are separate work.
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