Modernisation should move up the priority list when certificate counts are high, lifecycles are shrinking, manual handling is common, or outages are already appearing. At that point, delaying automation increases both security risk and operational cost.
Why This Matters for Security Teams
Modernising PKI is not just a technical refresh. It becomes a priority when certificate volume, renewal speed, and business criticality outgrow what manual issuance and spreadsheets can safely support. Legacy workflows often look acceptable until a renewal window is missed, a CA change creates confusion, or a revocation event exposes how slow the process really is. That is why certificate operations now sit alongside broader NHI governance, not outside it. The lifecycle issues called out in Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs are the same warning signs that drive PKI modernisation.
From a governance standpoint, PKI should be treated as an identity service for machines, services, workloads, and agents, not as a background utility. The NIST Cybersecurity Framework 2.0 reinforces the need to identify, protect, detect, respond, and recover in a way that reflects operational reality. When certificates are deeply embedded in authentication, encryption, signing, and workload trust, delay turns a maintenance issue into an availability and compromise problem. In practice, many security teams encounter PKI failures only after an expired certificate or broken chain has already disrupted production.
How It Works in Practice
The decision to modernise usually starts with a simple inventory question: how many certificates exist, who owns them, where they are installed, and how they are renewed. If that answer is incomplete, legacy processes are already creating risk. Modern PKI programmes centralise discovery, issuance policy, renewal, and revocation so that certificates can be managed as part of a governed lifecycle rather than one-off exceptions. That lifecycle view aligns with Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs, especially where service accounts, API keys, and certificates coexist in the same machine identity estate.
In practice, modernisation often includes:
- Automated enrolment and renewal for high-volume certificates
- Policy-driven certificate profiles for different workloads and trust levels
- Shorter validity periods paired with reliable orchestration
- Revocation workflows that are fast enough to matter operationally
- Visibility into ownership, expiry, and dependency chains
Security teams should also align PKI changes with enterprise control expectations. The NIST Cybersecurity Framework 2.0 is a useful reference for mapping identity, protection, and recovery requirements to certificate operations. A modern PKI stack should reduce touchpoints, not just move them to a different console. It should also support automation for cloud, on-premises, and CI/CD environments where workloads spin up and down faster than humans can process approvals. These controls tend to break down when certificate ownership is unclear and renewal still depends on manual tickets because expiry is then discovered too late to prevent outage.
Common Variations and Edge Cases
Tighter certificate control often increases operational overhead at first, requiring organisations to balance stronger assurance against migration effort and tool sprawl. That tradeoff is especially visible when legacy applications cannot handle short-lived certificates, pinned trust chains, or automated renewal. Current guidance suggests modernising the highest-risk and highest-volume paths first rather than forcing a big-bang PKI replacement. For many enterprises, that means prioritising externally exposed services, administrative access paths, and workloads that already depend on continuous availability.
There is no universal standard for the ideal certificate lifetime yet, and best practice is evolving as automation improves. Some environments still need transitional coexistence between old and new CAs, but that should be treated as a bridge, not a destination. The same applies to hybrid estates where hardware security modules, offline root CAs, and regulatory controls slow change. In those cases, the question is not whether legacy processes can be preserved indefinitely, but whether they can survive another audit cycle without creating renewal risk or delayed revocation.
One useful signal is organisational dependency on manual knowledge. If only a few administrators understand the trust hierarchy, if outages have already come from missed renewals, or if certificate sprawl is feeding broader NHI exposure, then the business case for modernisation is already strong. The lifecycle and visibility concerns documented in Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs show why waiting usually shifts cost from planned transformation to reactive recovery.
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 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 weakness in machine credentials. |
| NIST CSF 2.0 | PR.AC-1 | PKI modernisation improves identity proofing and access trust for workloads. |
| NIST Zero Trust (SP 800-207) | SC-7 | Modern PKI supports stronger trust boundaries and reduces implicit reliance. |
Use certificate-backed trust to verify each workload connection instead of assuming network location.
Related resources from NHI Mgmt Group
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- How should organisations modernise IGA without creating more manual work?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on May 27, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
