Zero trust matters because perimeter security assumes trust once a user or device is inside the network, which fails during identity-based attacks. In manufacturing, attackers can pivot from IT systems into production support, erode availability, and create supply chain knock-on effects. Continuous verification, least privilege, and strict lateral movement controls reduce that exposure.
Why This Matters for Security Teams
Manufacturing and industrial environments cannot rely on perimeter trust when identity is the attack path. Once an attacker compromises a user, service account, API key, or automation credential, they can move from business systems into OT-adjacent support services, engineering tools, or remote maintenance workflows. That is why NIST’s NIST SP 800-207 Zero Trust Architecture remains relevant: access must be continuously evaluated, not assumed after network admission.
NHIMG’s Ultimate Guide to NHIs notes that 90% of IT leaders say properly managing NHIs is essential for a successful zero-trust implementation, which is especially true in industrial settings where service accounts and secrets often outnumber human identities. The practical issue is not only credential theft, but also lateral movement into systems that influence availability, safety, and supplier operations. In practice, many security teams encounter identity-driven production disruption only after a maintenance account or automation token has already been abused, rather than through intentional testing.
How It Works in Practice
zero trust in manufacturing is less about a slogan and more about narrowing what any identity can do at runtime. That means verifying the requester, limiting scope to the exact task, and requiring fresh authorization for sensitive actions. For human users, this often includes strong authentication, device posture, and role reduction. For machines and agents, it means workload identity, short-lived credentials, and policy checks tied to context rather than static network location.
Current guidance suggests treating production support, MES, ERP, engineering workstations, and remote vendor access as separate trust domains. A service account that reads telemetry should not also be able to modify PLC-adjacent systems. Secrets should be vaulted, rotated, and revoked quickly, with one identity per application or service rather than shared credentials across plants. NHIMG’s 52 NHI Breaches Analysis shows how often compromise starts with weak identity hygiene, while the Guide to SPIFFE and SPIRE explains why cryptographic workload identity is a better primitive than long-lived secrets for service-to-service trust.
- Use least privilege at the identity level, not just the network segment level.
- Issue short-lived secrets or tokens for maintenance, automation, and integrations.
- Continuously re-evaluate access when context changes, such as a new location, device, or task.
- Log and review every privileged action that could affect availability or safety.
These controls tend to break down when legacy OT integrations depend on shared accounts, static credentials, or flat remote access paths because the environment cannot express per-request authorization cleanly.
Common Variations and Edge Cases
Tighter zero-trust control often increases operational overhead, requiring organisations to balance resilience against uptime constraints and vendor support realities. That tradeoff is especially visible in brownfield plants, where older systems may not support modern authentication, mutual TLS, or per-request policy checks. In those cases, guidance suggests compensating controls such as segmentation, jump hosts, credential brokering, and strict monitoring until the legacy dependency can be reduced.
There is no universal standard for zero trust in OT, so the right pattern depends on how much production logic is tied to identity. Remote OEM maintenance, temporary contractors, and machine-to-machine integrations are common edge cases because they create bursty access that looks legitimate but should still expire quickly. NHIMG’s Why NHI Security Matters Now and the Top 10 NHI Issues both reinforce the same operational lesson: if an identity can be reused, shared, or left active after the job ends, zero trust has not been fully applied.
Best practice is evolving, but the direction is clear. Start by eliminating standing privilege, then move toward short-lived access, explicit approval for high-risk actions, and tighter separation between IT and plant-floor trust domains.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and CSA MAESTRO address the attack and risk surface, while NIST CSF 2.0, NIST Zero Trust (SP 800-207) and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | PR.AC-4 | Least privilege and access management are central to zero trust in industrial environments. |
| NIST Zero Trust (SP 800-207) | Defines the zero trust model for continuous verification and denied implicit trust. | |
| OWASP Non-Human Identity Top 10 | NHI-03 | Secret rotation and short-lived credentials reduce exposure from compromised machine identities. |
| CSA MAESTRO | Maps to agentic and workload identity controls for autonomous industrial automation. | |
| NIST AI RMF | GOVERN | Governance is required to assign accountability for autonomous and automated access paths. |
Document ownership, review, and monitoring for all automated identities and privileged workflows.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on August 26, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
