1) First rule: OT is not IT

In gas and power plants, availability and safety come first. A security control that causes downtime, false trips, or operational disruption can be more dangerous than the cyber risk it tries to reduce. That’s why OT security must be risk-aware and operations-friendly.

OT mindset: Observe → understand process → reduce risk → avoid disruption.

2) Step 1 — Visibility (Know what exists)

You can’t defend what you can’t see. In many OT environments, asset inventory is incomplete, network diagrams are outdated, and legacy devices are undocumented.

  • Identify OT assets: PLCs, HMIs, engineering workstations, historians, servers, network gear.
  • Map communication: who talks to whom, which ports/protocols, and why.
  • Document “normal”: expected traffic patterns and operational states.

3) Step 2 — Segmentation (Reduce blast radius)

Segmentation is one of the highest ROI controls in OT. The goal is to prevent an IT-side incident from easily reaching critical control zones.

  • Separate IT and OT networks with controlled interfaces.
  • Use zone/conduit thinking (e.g., corporate → DMZ → control zones).
  • Allow only required traffic (least privilege networking).
Simple test: If ransomware hits the office network today, can it reach PLCs or HMIs tomorrow?

4) Step 3 — Monitoring (Detect before damage)

OT monitoring is not just “security monitoring” — it’s operational monitoring plus cyber context. Start with low-risk monitoring that does not interfere with operations.

  • Passive network monitoring (SPAN/TAP) for visibility.
  • Baseline normal traffic and detect deviations.
  • Log critical systems: engineering workstations, jump hosts, historians, remote access.

5) Step 4 — Incident readiness (Plan before the crisis)

In OT, incident response is not only “contain and clean.” It must coordinate with operations. You need pre-agreed actions, roles, and safe decision paths.

  • Define “what to isolate” without stopping the plant.
  • Create procedures for safe shutdown / fail-safe if needed.
  • Ensure backups and recovery plans exist for critical OT systems.

6) Where AI fits (Anomaly detection that operators trust)

AI can help detect subtle anomalies in time-series telemetry and network behavior, but only if alerts are meaningful. In OT, a “high anomaly score” is useless unless it maps to process context.

  • Start with simple baselines: thresholds, seasonal patterns, moving averages.
  • Progress to ML: isolation forest, LSTM/Autoencoder, change-point detection.
  • Always explain: what changed, where, when, and why it matters operationally.
My focus: explainable, process-aware anomaly detection that reduces false positives.

7) A practical 30-day plan (beginner → real progress)

  • Week 1: Learn OT basics + Purdue model + common OT assets.
  • Week 2: Network basics + traffic visibility + baseline thinking.
  • Week 3: Build a small dataset (or simulate) + baseline anomaly detection.
  • Week 4: Document architecture + threats + mitigations + lessons learned.

Closing

OT/ICS cybersecurity for gas and power is about protecting safety and continuity. The strongest security strategies respect operations and reduce risk without disruption. This roadmap is how I structure my own journey: field reality → focused learning → applied projects.

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