Why do non-human identities matter in critical infrastructure risk planning?

Non-human identities often control the systems that keep infrastructure running, including APIs, service accounts, and automation tools. If those identities are over-privileged or poorly monitored, compromise can affect availability and not just data confidentiality. They therefore belong in resilience planning, not only in technical access reviews.

Why This Matters for Security Teams

Non-human identities matter in critical infrastructure because they often carry the actual operational authority behind monitoring, orchestration, failover, and service-to-service communication. When a service account, API token, or automation identity is compromised, the impact can move quickly from isolated access abuse to disruption of essential functions. That is why NHI belongs in resilience planning, not just access governance, and why frameworks such as the NIST Cybersecurity Framework 2.0 are useful for connecting identity controls to broader protective and recovery outcomes.

Security teams sometimes treat NHI as a back-office administration issue, but critical infrastructure operators face a different risk profile. Many assets are automated, interdependent, and latency-sensitive, so excessive privilege or weak rotation can create a single point of failure at scale. Current guidance suggests that NHI governance should be linked to asset criticality, operational dependencies, and incident response playbooks rather than handled as a one-time inventory exercise.

In practice, many security teams encounter NHI risk only after an outage, a suspicious automation event, or a credential misuse investigation has already exposed the dependency.

How It Works in Practice

Effective planning starts with an inventory of every non-human identity that can affect production systems, including machine accounts, workload identities, secrets, certificates, and tool integrations. Each identity should be mapped to the service it supports, the systems it can reach, the owner responsible for it, and the business function that would fail if it were unavailable. That mapping turns NHI from a technical artifact into an operational risk object.

Controls then need to be layered around lifecycle, privilege, and observability. Lifecycle controls cover issuance, rotation, expiry, and revocation. Privilege controls should enforce least privilege, short-lived access where possible, and separation between build, test, and production environments. Observability should detect unusual patterns such as new source locations, atypical API call volume, failed authentication bursts, or privilege escalation paths. For infrastructure operators, this is especially important where a single identity can control many downstream systems. Relevant techniques also appear in incident response and threat modelling guidance from CISA cyber threat advisories and in the attack-pattern thinking reflected by ENISA Threat Landscape.

• Classify NHI by criticality, not just by system of record.
• Assign an owner and recovery path for each identity.
• Limit standing privilege and prefer short-lived credentials where architecture allows.
• Log authentication, token use, and privileged actions separately from application telemetry.
• Test what happens when an identity is revoked, rotated, or misused during an exercise.

This is also where agentic AI is starting to intersect with critical infrastructure, because autonomous tools may inherit execution authority, use secrets, and trigger downstream actions. Emerging work such as Anthropic Project Glasswing reflects the growing need to govern AI-connected identities as part of the same operational model. These controls tend to break down when legacy systems rely on shared credentials and no single team can prove which automation path actually owns the production action.

Common Variations and Edge Cases

Tighter identity control often increases operational overhead, requiring organisations to balance availability against rotation frequency, approval latency, and recovery complexity. That tradeoff is real in critical infrastructure, where some systems cannot tolerate frequent restarts or synchronous secret replacement.

Best practice is evolving for environments that still depend on shared service accounts, embedded credentials, or vendor-managed automation. In those cases, the priority is not perfect elimination overnight but reducing blast radius, documenting compensating controls, and creating a migration path toward scoped identities and monitored secrets. The EU NIS2 Directive is relevant where operational resilience obligations require stronger governance over essential services and dependencies.

There is also no universal standard for how to treat ephemeral identities created by orchestration platforms, containers, or AI-driven automation. Current guidance suggests treating them as first-class identities if they can influence production state, even when they exist only briefly. That approach is particularly useful for stress testing, because it highlights which processes can fail safely and which ones can cascade across the environment.

For organisations that handle regulated or cross-border infrastructure, the practical question is not whether NHIs exist, but whether they are visible enough to be restored, constrained enough to be trusted, and monitored enough to detect misuse before service degradation becomes a public incident.

Related resources from NHI Mgmt Group

• Why does quantum risk matter for non-human identities now?
• When do non-human identities pose the greatest risk to organizations?
• Why do non-human identities create more risk than many human accounts?
• Why do non-human identities increase zero trust risk?