Closing the gap in OT cybersecurity with a universal trust model

After recently participating in the ICS/SCADA Cybersecurity Symposium in Chicago and discussing industrial cybersecurity with operators, vendors, and security professionals, one thing became crystal clear: we’re approaching a tipping point in operational technology (OT) security. A convergence of mounting cyberthreats, widespread device exposure, and evolving regulatory guidance isn’t just creating challenges—it’s fundamentally reshaping how we need to think about trust in critical infrastructure.

The statistics are sobering. Let’s take one example and look at security cameras. There are over 40,000 of them worldwide that are exposed to the internet, with more than 14,000 in the US alone. The telecommunications sector accounts for 79% of exposed cameras, followed by technology (28.4%), media/entertainment (19.6%), and utilities (11.9%). 

But here’s what keeps me up at night: these cameras aren’t just surveillance devices anymore; they’re a huge attack surface and potential pivoting point into our most critical operational networks.

Why traditional OT security is faltering

Let me dive into what we’re really dealing with. Take the June 2025 ICS Patch Tuesday revelations: Siemens identified CVE-2025-40585, a critical default credentials issue that could allow attackers to gain remote control of energy services components. 

Critical vulnerabilities in Simatic S7-1500 CPUs required emergency updates. Four vulnerabilities were patched in EVLink WallBox electric vehicle charging stations, including ones enabling arbitrary file access and remote-control takeover.

This isn’t just about individual vulnerabilities. It’s about a fundamental architectural problem. The traditional approach to OT security, built around hierarchical layers served us well when operational technology lived in isolated islands. 

But today’s reality is vastly different. Sensors and actuators have become “smart” as they’ve got computing power, data storage capabilities, and they’re managing tasks like calibration and self-diagnostics autonomously. More importantly, they’re communicating directly with vendor monitoring software in the cloud via cellular networks, completely bypassing the carefully constructed security perimeters.

When a predictive maintenance system needs to communicate from Level 0 (physical process) directly to Level 5 (cloud solutions), our traditional security model breaks down. We’re forced into uncomfortable compromises: either maintain essential connectivity and accept security risks, or maintain security isolation and lose critical functionality and interoperability.

CISA gets it, but their guidance reveals bigger problems

CISA’s May 2025 guidance provides clear direction, and I applaud their emphasis on the fundamentals. Their key recommendations of network isolation, access control, network segmentation, and maintaining manual operations capabilities are mission critical. But here’s what struck me during our Chicago discussions: even when organizations follow CISA’s guidance perfectly, they still face the fundamental challenge of maintaining trust across security domains.

CISA recognizes that “cyber threat actors use simple, repeatable, and scalable toolsets available to anyone with an internet browser.” Their solution? Remove OT connections to the public internet because “OT devices lack authentication and authorization methods resistant to modern threats.”

That last part is the key insight. It’s not that we need better firewalls or more sophisticated network segmentation—though those remain important. The real issue is that our OT devices fundamentally lack the authentication and authorization methods needed for today’s threat landscape.

TEIA and a different way to think about trust

This is where TEIA’s universal trust model represents a paradigm shift. Instead of treating security as another layer to be added on top of existing systems, we’re proposing a fundamental change in how devices, systems, and networks establish and maintain trust relationships.

Think about it this way: in the traditional model, once a message crosses from one security zone to another, we lose cryptographic proof of its authenticity and integrity. We might know it came through our firewall, but we can’t prove it hasn’t been tampered with after that point. With TEIA’s approach, every message is cryptographically secured and signed, attesting to the message provenance and authenticity, from the originating source to the final destination, regardless of how many networks, gateways, or security boundaries it crosses to get there.

Now let’s bring this into focus with a hypothetical example of a power generation company. Let’s say they’ve been maintaining 20-year-old SCADA systems across 12 facilities, facing regulatory pressure to meet IEC 62443 compliance between their sites and with the governing ISO. The traditional approach would have required more than $8M in hardware upgrades, significant operational disruptions and higher ongoing operation costs thereafter.

Here is where TEIA’s message-level security can act as a bridge between their legacy OT and modern IT systems. The legacy components can remain within their secure zones while TEIA-enabled gateways can provide secure and attestable communication paths between them. By our estimation, full compliance can be achieved here with little more than $2M invested, and that’s with zero operational disruptions—and a transformative reduction in identified security vulnerabilities, enhanced visibility into cross-domain traffic with attestability to meet compliance and regulatory obligations.

Having your cake and eating it too

Here’s where TEIA fundamentally changes the game: you no longer have to choose between connectivity and security. That predictive maintenance link to your vendor? That direct communication path from smart sensors to cloud analytics? That integration with third-party monitoring systems? You can have all of that while maintaining zero-trust assurance.

Consider another example: a regional grid operator is looking to add 500MW of distributed solar and wind to their system. Their legacy energy management system (EMS) is unable to securely communicate with the renewable assets, causing manual interventions and a substantial curtailment of approximately 8%.  

With TEIA securely bridging their legacy EMS and renewable assets, they can reduce curtailment to under 2% and effectively recover 30MW of additional capacity—worth approximately $4.5M annually. Most importantly, they can maintain regulatory compliance with a full audit trail of all communications.

Regulatory alignment that’s made to order

One of the things that excites me about where we are today is the alignment between TEIA’s technical approach and regulatory expectations. CISA’s framework supports comprehensive security controls to address advanced threat actors who pivot through enterprise networks to reach OT systems. TEIA’s universal trust model and zero-trust architecture provide exactly that—comprehensive solution that addresses current threats while enabling future interoperability requirements.

We’re not asking organizations to rip and replace their existing security investments. IEC 62443 provides robust frameworks for system-level security—TEIA complements that by providing the secure communication protocol that satisfies many of the technical control requirements, particularly for cross-domain communication.

Brighter future for OT security

The opportunity ahead of us is significant. We’re seeing three critical trends converging that create a new transformation in OT security.

First, the sheer scale of exposed infrastructure is creating urgent security imperatives that can no longer be ignored. With tens of thousands of unprotected OT devices worldwide, many connected directly to cloud services via cellular networks, the traditional approach of hoping our perimeter defenses will hold is simply not sustainable. These devices aren’t just potential entry points—they’re already being actively exploited as pivoting mechanisms into critical operational networks.

Second, we finally have regulatory clarity about what needs to be done. CISA’s guidance provides clear, actionable direction that acknowledges the reality of modern OT environments. Their recognition that “OT devices lack authentication and authorization methods resistant to modern threats” validates what many of us have been saying for years—we need fundamental changes to how trust relationships are established and maintained, not just better perimeter defenses.

Third, and perhaps most importantly, we now have the technology readiness to solve these problems. TEIA’s universal trust model provides a practical implementation pathway that doesn’t require organizations to abandon their existing security investments or disrupt critical operations. Instead, it provides the missing piece—cryptographic proof of authenticity and integrity across all domains—that makes secure interoperability possible.

Our recommended approach is straightforward:

Phase 1: Identify OT devices currently exposed to public networks and assess compliance with CISA’s priority mitigations.

Phase 2: Implement TEIA’s message protocol for secure device-to-device and device-to-cloud communication via TEIA security associations established for relevant OT device interactions.

Phase 3: Integrate TEIA with existing standards (IEC 61850, DNP3, Modbus) to enable secure data sharing between previously isolated OT systems.

A pivotal moment

We’re at a crossroads for OT security. Traditional perimeter-based methods served us well when operational technology existed in isolation, but today’s interconnected reality demands a new approach. TEIA’s universal trust model isn’t just another security tool—it’s a fundamental shift in how we think about trust relationships in critical infrastructure.

The choice is clear: we can continue patching vulnerabilities in an inherently vulnerable architecture, or we can adopt a new trust model that provides cryptographic proof of authenticity and integrity across all domains.

For organizations serious about securing their operational technology while maintaining essential connectivity, TEIA represents the path forward. The regulatory alignment is there, the technology is proven, and the business case is compelling where we can make the change and stay ahead of OT threats or forever play catchup.