OT Cybersecurity: Is the Purdue Model Still Useful?

Podcast: Industrial Cybersecurity InsiderEpisode: OT Cybersecurity: Is the Purdue Model Still Useful?Pub date: 2026-05-12Get Podcast Transcript →powered by Listen411 - fast audio-to-text and summarizationIs the Purdue Model outdated, or simply misunderstood? In this episode, Dino sits down with Ken Kully (Rockwell Automation) for a candid, practitioner-level conversation about what the Purdue Model still gets right.They discuss where it falls short in modern environments, and why “IT/OT convergence” remains more of a people-and-process challenge than a technology problem. They break down the reality on the plant floor: long-lived legacy systems, inconsistent architectures across sites, limited maintenance windows, and the operational consequences of downtime. The discussion also tackles the everyday friction points: MFA, shared operator accounts, unmanaged vendor laptops, and remote access “surprises”, and why you can’t improve OT security posture without a trustworthy asset inventory and segmentation that keeps systems “in their lane.”Chapters:(00:00:00) Intro + why this Purdue conversation matters now(00:01:00) Ken’s background: from process environments to OT cyber delivery readiness(00:04:00) The big question: has the Purdue Model outlived its usefulness?(00:07:00) Framework vs. strict blueprint: “Purdue enough” in real plants(00:09:00) IT/OT convergence: why it’s a people + process problem (not tech)(00:12:00) The “silver tsunami” and why security UX fails on the plant floor(00:15:30) MFA, shared logins, and why “security gets in the way” still shows up(00:18:00) Legacy reality: Windows 98/7 boxes, vendor lock-in, and downtime economics(00:21:00) Discovery first: diagrams, configs, and why documentation is always missing(00:23:30) Purdue as a map: brokering traffic, one-up/one-down, and the “3.5” DMZ(00:26:00) When devices try to “escape the box”: unexpected outbound comms + exposure risk(00:28:30) Vendor/OEM access: the unmanaged laptop problem in OT(00:32:00) Asset inventory as the unlock: you can’t defend what you don’t know exists(00:34:00) Why IT often won’t “crawl the plant,” and what that means operationally(00:36:30) Scale problem: 30 plants, 30 realities—standardize globally, execute locally(00:38:30) The SI/OEM “third leg”: why trusted integrators are key to sustainable OT security(00:40:30) Closing + crossover: continuing the discussion on Ken’s OT After Hours podcastLinks And Resources:Kenneth Kully on LinkedInWant to Sponsor an episode or be a Guest? Reach out here.Industrial Cybersecurity Insider on LinkedInCybersecurity & Digital Safety on LinkedInBW Design Group CybersecurityDino Busalachi on LinkedInCraig Duckworth on LinkedInThanks so much for joining us this week. Want to subscribe to Industrial Cybersecurity Insider? Have some feedback you’d like to share? Connect with us on Spotify, Apple Podcasts, and YouTube to leave us a review!The podcast and artwork embedded on this page are from Industrial Cybersecurity Insider, which is the property of its owner and not affiliated with or endorsed by Listen Notes, Inc.