They should treat PKI as a lifecycle governance problem, not a one-time deployment. Start with complete certificate and key inventory, then standardise issuance, renewal, and revocation across cloud and on-prem systems. If the organisation cannot produce consistent evidence for each trust object, the audit problem will persist even when encryption is technically sound.
Why This Matters for Security Teams
PKI audit failures in hybrid environments usually are not caused by weak encryption. They happen when certificate ownership, issuance, renewal, and revocation are spread across cloud consoles, on-premises tooling, and application teams with no shared evidence trail. That creates gaps auditors flag immediately: unknown certificate sprawl, expired trust objects, inconsistent key protection, and no reliable proof of who approved what.
The problem is broader than a single control failure. PKI touches asset inventory, access governance, change management, and incident response, which is why the NIST Cybersecurity Framework 2.0 and the Ultimate Guide to NHIs — Regulatory and Audit Perspectives both point toward lifecycle accountability rather than isolated certificate checks. NHIMG’s research shows that lack of credential rotation is cited as the top cause of NHI-related attacks by 45% of organisations, which is a useful warning sign for PKI too.
In practice, many security teams discover certificate drift only after an audit request forces them to reconcile systems that were never designed to produce the same answer twice.
How It Works in Practice
Reducing PKI audit failure starts with a complete trust-object inventory: certificates, issuing CAs, private keys, intermediates, service accounts that consume certificates, and any automation that renews them. The point is not just to count assets, but to assign ownership, location, expiry, purpose, and revocation path. Without that baseline, hybrid PKI becomes a collection of local exceptions that cannot be evidenced consistently.
From there, standardise the lifecycle. Align issuance criteria, approval workflows, renewal windows, and revocation triggers across on-prem and cloud systems. Where possible, use policy-driven automation so renewal and revocation are not dependent on manual ticket handling. The NHI Lifecycle Management Guide and the NIST Cybersecurity Framework 2.0 both support this operational model: know what exists, define who owns it, and prove that it is maintained throughout its life.
- Inventory every certificate and key store across cloud, containers, endpoints, and legacy systems.
- Map each certificate to a business service, owner, issuing authority, and renewal schedule.
- Automate renewal where feasible, but keep revocation and exception handling under explicit governance.
- Retain evidence of issuance, approval, rotation, and revocation in a central audit trail.
- Test that expired, duplicated, or orphaned certificates are detected before auditors find them.
Security teams should also align PKI monitoring with broader NHI governance. The same audit logic that applies to service account sprawl and stale secrets applies to certificate sprawl, especially when identity data is split across cloud IAM, internal PKI, and third-party platforms. These controls tend to break down when legacy applications still depend on manually installed certificates because renewal and revocation cannot be automated without service interruption.
Common Variations and Edge Cases
Tighter PKI governance often increases operational overhead, requiring organisations to balance auditability against legacy compatibility and release speed. That tradeoff is real in hybrid estates where some workloads can adopt short-lived certificates while others still require long-lived trust chains.
Best practice is evolving, but current guidance suggests treating exceptions as temporary and documented, not as permanent policy. For example, a cloud-native workload can often support automated rotation and central policy enforcement, while a mainframe, industrial system, or vendor-managed appliance may need compensating controls such as stricter access review, segmented trust boundaries, and manual evidence collection. The Top 10 NHI Issues is useful here because certificate governance often overlaps with the same root causes seen in broader NHI failures: missing visibility, weak rotation, and unclear ownership.
Audit failure also becomes more likely when multiple teams issue certificates independently, when external partners bring their own trust chains, or when revocation checking is inconsistently enforced across environments. In those cases, the question is no longer whether PKI is deployed, but whether the organisation can prove consistent control over every trust object across its full lifecycle.
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, NIST AI RMF and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Covers rotation and lifecycle control for non-human credentials and trust objects. |
| NIST CSF 2.0 | ID.AM-1 | Asset inventory is foundational to proving PKI coverage in audits. |
| NIST AI RMF | Govern function supports evidence, accountability, and lifecycle oversight for hybrid PKI. | |
| NIST Zero Trust (SP 800-207) | SC-12 | Zero trust requires strong credential and key management across environments. |
Inventory certificates and enforce automated rotation, revocation, and expiry tracking under NHI-03.
Related resources from NHI Mgmt Group
- How should security teams govern access changes across hybrid identity environments?
- How should security teams prioritise NHI remediation in cloud environments?
- How should security teams govern non-human identities in cloud environments?
- How should security teams reduce standing privilege in hybrid environments?
