Are you treating your weapon systems and operational technology (OT) like standard IT endpoints? If so, your Zero Trust strategy already has a gap—and it sits exactly where your highest-consequence missions live.
Zero Trust has moved from a theoretical concept to a strict mandate. The DoD Zero Trust Strategy and Reference Architecture, paired with the November 2025 OT guidance and its 84 OT-specific activities and FY2030 target, makes “assume breach” a policy requirement, not a conference slogan. Forrester’s new report, “A Practical Guide to Zero Trust Implementation,” gives leaders a clear way forward. But on the ground, the hardest problems still surface at the boundaries—OT networks, TS/SCI crossings, and coalition data sharing—where traditional IT assumptions break down.
This article pulls a few key themes from Forrester’s guide and shows where hardware-enforced security plays a critical role. For the full analysis and recommendations, we strongly suggest reading the Forrester report itself.
Compliance Isn’t the Same as Resilience
Mandates like the DoD Zero Trust Strategy set the floor. They tell you what to implement and by when. But meeting a milestone on a maturity model doesn’t mean your mission keeps running when something goes wrong.
Forrester frames Zero Trust as more than a checklist. It’s a model for staying operational under stress—even when individual controls or credentials fail. That distinction matters everywhere, but it matters most where downtime means physical disruption, mission degradation, or lost operational advantage.
The shift in mindset is simple to state and hard to execute:
- Move from “keep bad things out” to “assume breach.”
- Design systems so a single compromise doesn’t flatten your trust zones.
- Treat resilience—not the audit—as the real goal.
Compliance proves a point in time. Resilience holds the boundary over time.
Where Forrester’s Roadmap Hits Its Limits in OT
Forrester’s guide lays out a practical roadmap across seven domains: users, devices, networks and environments, applications and workloads, data, visibility and analytics, and automation and orchestration. For enterprise IT, that logic holds. You can inventory assets, deploy agents, normalize logging, and tighten policy without taking the mission offline.
At OT and cross-domain boundaries, the curve looks very different. DoD’s OT guidance mirrors the same Zero Trust pillars but adapts them for legacy equipment, safety and uptime constraints, and specialized operators. It says plainly: the core principles still apply, but adoption is harder in OT.
Here’s why a copy-paste from IT fails:
- You often can’t deploy endpoint agents on proprietary or safety-certified systems.
- You can’t always perform deep inline inspection without risking uptime.
- You can’t rotate credentials at enterprise cadence on decades-old control systems.
So your most realistic first move isn’t agent rollout—it’s boundary-centric. Discover where data actually crosses trust zones, then rank which of those crossings are high-risk candidates for hardware-enforced controls.
When Software Segmentation Needs Hardware Fire Doors
Segmentation sits at the heart of every Zero Trust model. When identity, workload, and policy controls fail, segmentation is what limits lateral movement. In enterprise environments, that usually means microsegmentation and identity-aware access at logical chokepoints.
But sophisticated attackers increasingly move with valid credentials and allowed workflows. When segmentation lives only in software, one policy error or credential compromise can flatten your zones from the adversary’s point of view.
A clearer mental model: software controls are the alarms and sensors. Hardware-enforced boundaries are the fire doors. Even when monitoring fails or credentials are abused, those doors stop a breach from spreading across trust zones.
That’s the architectural gap hardware closes:
- Data diodes create physically one-way links, so nothing can signal back into a protected enclave—even if software controls are compromised.
- Protocol Filtering Diodes (PFDs) like Owl Talon extend that physical separation with protocol-aware inspection, controlling exactly what content is allowed to flow out.
- Cross-domain solutions sit where data crosses classifications or trust zones, enforcing content filtering, protocol validation, and policy at the boundary. XD Bridge ST, for example, terminates sessions on each side, passes only inspected content across the diode, and re-originates it—so no end-to-end session ever spans domains.
DoD’s OT guidance reflects this reality, explicitly accommodating environments where agent-based monitoring is impractical and aligning with Raise the Bar (RTB) expectations for hardware-enforced separation.
When you can’t reliably control the endpoint, Zero Trust shifts to the moment data crosses a boundary. In a GEOINT workflow, a cross-domain solution can enforce which products move from TS/SCI to Secret, strip disallowed formats, and log every transfer. In a SCADA setting, a data diode can push telemetry one way from the process network to the SOC—enabling visibility while physically blocking command traffic from flowing back. The control objectives stay the same. The enforcement point moves to the crossing itself.
A Three-Year Boundary Plan You Can Fund
Forrester recommends a multi-year roadmap that aligns with existing programs and produces measurable outcomes. DoD’s OT guidance adds the policy driver, with a horizon stretching to FY2030. Together, they support a practical plan that PEOs, PMs, and Zero Trust leaders can defend to boards and budget owners.
Year 1 — Discover. Complete a boundary inventory. Identify and rank your most critical flows: TS/SCI to Secret, OT to SOC, weapon system to C2, and coalition exchange. Map each to Forrester’s seven domains and to the OT activities that matter most.
Year 2 — Enforce. Deploy hardware-enforced controls at the highest-risk crossings. Standardize repeatable patterns—one-way telemetry, controlled low-to-high transfer, OT monitoring paths—and integrate them with your existing identity and network controls.
Year 3 — Integrate and Govern. Feed boundary telemetry into your visibility and analytics workflows. Formalize governance, document outcomes, and show how boundary controls support broader Zero Trust milestones and OT modernization timelines.
Strong boundaries also act as stabilizers. They change less often than software stacks, create clear and auditable enforcement points, and reduce the retuning required when the surrounding environment shifts. That buys you time and flexibility to adopt newer analytics and cryptographic approaches without redesigning your riskiest crossings first.
Turn the Roadmap Into Hardware-Backed Reality
Forrester’s guide helps you prioritize domains, set maturity targets, and justify a multi-year program. The missing piece for OT, coalition, and classified environments is a commitment to enforce the riskiest crossings in hardware—so identity, network, and data controls are never your last line of defense.
A plan that stops at software is a maturity model on paper. A plan that embeds hardware-enforced boundaries at key crossings is an architecture that can absorb compromise and keep missions running.
At Owl Cyber Defense, that’s our focus. Our Owl Talon data diodes, XD Bridge ST, and cross-domain solutions help programs apply Zero Trust thinking right where the roadmap meets contact with real OT, mission systems, and the tactical edge.
Want the full Forrester analysis?
Download the report, “A Practical Guide to Zero Trust Implementation,” and see how hardware-enforced boundaries turn your Zero Trust roadmap into an architecture that holds.
