Security teams should govern certificates as identities with owners, lifecycles, and revocation triggers, not as static configuration files. That means linking issuance to approved use cases, enforcing expiry and renewal, and revoking certificates when a device, vendor, or system is retired. Without lifecycle control, certificate-based authentication can preserve stale trust instead of reducing risk.
Why This Matters for Security Teams
Certificates are often treated as a technical detail, but in machine and device authentication they function as long-lived identity assertions. That makes them subject to the same governance failures that affect any identity system: weak ownership, poor inventory, missed revocation, and ambiguous retirement. NIST Cybersecurity Framework 2.0 emphasizes identity and access as part of operational resilience, not a one-time configuration step, and NHIMG’s State of Non-Human Identity Security shows why that matters: only 1.5 out of 10 organisations are highly confident in securing NHIs.
The practical risk is stale trust. A certificate can remain valid long after the device, workload, vendor, or integration it authenticates should no longer be trusted. That creates hidden access paths that are difficult to detect because certificates are designed to be machine-readable, not human-obvious. Security teams should therefore govern certificates as identities with a lifecycle, not as static configuration files. In practice, many teams discover certificate risk only after an expired, orphaned, or unrecalled credential has already disrupted service or preserved unauthorized access.
How It Works in Practice
Effective governance starts with assigning every certificate to an owner, a purpose, and a retirement condition. That means linking issuance to an approved use case, defining where the certificate may authenticate, and recording the system or device it represents. The certificate should be treated as a workload or device identity, with the same expectations around inventory, access review, and revocation that apply to other identities. The NHIMG lifecycle guidance for NHIs is useful here because it frames issuance, rotation, expiry, and decommissioning as one control loop rather than separate tasks.
From an operational standpoint, teams usually need four controls:
- Central inventory of certificates, owners, issuers, and expiry dates.
- Policy-based issuance that ties certificate approval to a business or technical need.
- Automated renewal and rotation with short enough validity to reduce exposure, but long enough to avoid avoidable outages.
- Revocation triggers for retirement, compromise, vendor offboarding, or system replacement.
For implementation detail, current guidance from NIST CSF 2.0 and related identity practices favors continuous oversight rather than periodic cleanup. Security teams should also look at certificate telemetry alongside dependency data so they can see which services will fail if a certificate is revoked. NHIMG’s Top 10 NHI Issues is a useful reference for common machine-identity failure modes, including weak ownership and poor visibility. These controls tend to break down in highly distributed environments with unmanaged edge devices, embedded systems, or third-party appliances that cannot support automated renewal and revocation workflows.
Common Variations and Edge Cases
Tighter certificate governance often increases operational overhead, so organisations must balance security benefit against renewal complexity and service availability. That tradeoff becomes more pronounced when certificates are embedded in firmware, vendor-managed appliances, or industrial devices that cannot be updated on a normal schedule. In those cases, best practice is evolving rather than universal: some environments can support short-lived certificates, while others need compensating controls such as network segmentation, stronger monitoring, and manual retirement playbooks.
Another common edge case is service-to-service authentication where certificates are used alongside other secrets or tokens. Security teams should avoid assuming that certificate expiry alone equals safety. If a certificate is replaced without removing the associated account, trust chain, or automation credential, stale access can remain. The NIST Cybersecurity Framework 2.0 supports this broader control view by tying identity governance to ongoing risk management. For organizations with limited visibility, NHIMG’s research on NHI security confidence gaps underscores the reality that inventory and ownership are often the first gaps to close before lifecycle automation can work reliably.
Where certificate governance breaks down most often is in legacy fleets, outsourced infrastructure, and environments where no one can confidently say which certificates are still active and which are only still valid.
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 address the attack and risk surface, while NIST CSF 2.0 and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Certificate rotation and expiry are core non-human identity lifecycle controls. |
| NIST CSF 2.0 | PR.AC-1 | Certificate auth is identity assurance and access control for machines. |
| NIST AI RMF | Machine and device certificates need governance, accountability, and lifecycle risk management. |
Establish ownership, monitoring, and lifecycle controls for certificate-based machine identities.
Related resources from NHI Mgmt Group
- How should security teams govern browser-based AI agents in SaaS environments?
- How should security teams govern certificate lifecycles across hybrid environments?
- How should security teams phase out password-based authentication without disrupting operations?
- How should security teams use context-based authentication in high-risk environments?
