Because certificates establish machine trust, not just encryption. When they authenticate services across delivery platforms, they function as non-human identities with lifecycle, ownership, and audit requirements. That puts them squarely inside IAM and NHI governance rather than outside it.
Why This Matters for Security Teams
Certificates are not just transport-layer plumbing. In application delivery, they are often the proof that one service, gateway, or automation component is allowed to talk to another, which means they create machine trust relationships that must be owned, reviewed, and revoked like any other identity. That shifts the problem from pure infrastructure hygiene into governance, especially when certificates are embedded in CI/CD, ingress, service meshes, and API gateways. NIST’s NIST Cybersecurity Framework 2.0 treats identity, access, and continuous oversight as core security outcomes, and the same logic applies to certificates.
NHIMG research shows why this matters operationally: in Ultimate Guide to NHIs, machine identities are framed as a lifecycle problem, not a point-in-time configuration task. The risk is not theoretical. The Critical Gaps in Machine Identity Management report found that 57% of organisations lack a complete inventory of their machine identities, which makes certificates hard to govern even before expiry, ownership, or compromise enter the picture. In practice, many security teams encounter certificate issues only after an outage, an audit finding, or an unexpected trust failure has already occurred, rather than through intentional identity governance.
How It Works in Practice
In modern delivery environments, certificates usually serve three roles at once: authentication, encryption, and authorization support. That makes them identity artifacts, not just crypto artifacts. A load balancer certificate, a mutual TLS client certificate, and a signing certificate in a build pipeline all represent different non-human identities with different owners, scopes, and expiration patterns. Current guidance suggests treating each one as an accountable asset with a defined issuer, consumer, purpose, and revocation path.
Operationally, strong certificate governance usually includes four controls:
- Inventory: discover every certificate across clusters, pipelines, appliances, and application runtimes.
- Ownership: assign a business and technical owner so renewal, revocation, and incident response do not stall.
- Lifecycle automation: use short-lived issuance, rotation, and revocation workflows rather than manual renewal.
- Policy enforcement: tie issuance rules to workload identity and approval logic, not to ad hoc requests.
This is where machine identity management converges with IAM. Certificates should align to the same lifecycle thinking described in Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs, because certificate expiry, key replacement, and trust anchor changes are governance events, not mere maintenance tasks. Mature programmes increasingly pair certificate automation with policy-as-code, so issuance and renewal happen only when the workload, environment, and request context are valid. That approach maps well to NIST Cybersecurity Framework 2.0 expectations for asset management, access control, and continuous monitoring.
When certificate management is weak, the failure mode is often systemic: expired certs break service-to-service traffic, stale certs linger after ownership changes, and untracked trust relationships persist in production. These controls tend to break down when certificates are embedded in legacy release processes, because no single team owns the full path from issuance to retirement.
Common Variations and Edge Cases
Tighter certificate governance often increases operational overhead, requiring organisations to balance automation speed against change control and incident response readiness. That tradeoff is especially visible in high-churn delivery environments such as microservices, Kubernetes, and ephemeral CI runners, where short-lived workloads create many more trust events than a traditional application stack.
There is no universal standard for how every certificate type should be governed yet. Best practice is evolving toward workload identity plus just-in-time issuance for ephemeral services, while long-lived root and intermediate certificates still demand stricter review, segregation, and recovery planning. A certificate used for service authentication in a mesh is usually a live identity control; a certificate used only to sign release artifacts may require a different approval path, but it still belongs in the same governance inventory.
NHIMG’s Top 10 NHI Issues and 52 NHI Breaches Analysis both reinforce a practical lesson: visibility and ownership failures are usually what turn certificate sprawl into security debt. The same is true when certificate sprawl crosses organisational boundaries, such as managed service providers, platform teams, or acquired business units. In those environments, governance breaks down because the identity control plane is fragmented, and revocation or replacement depends on multiple teams acting in sequence rather than through one policy source of truth.
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 CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Certificate lifecycle failures are machine identity failures. |
| NIST CSF 2.0 | PR.AC-1 | Certificates grant machine access and require governed identity assurance. |
| NIST CSF 2.0 | ID.AM-1 | Asset inventory is essential when certificates are embedded across delivery platforms. |
Treat certificates as access-bearing identities and continuously verify issuance, use, and revocation.
