They should use different controls for interactive users and non-human identities, but govern them through one access model. Enforce MFA and strong recovery for people, then inventory API keys, tokens, service accounts, and third-party access separately. The key is to remove standing privilege, shorten credential lifetime, and review delegated access on a fixed schedule.
Why This Matters for Security Teams
Unauthorized access rarely starts with a dramatic login event. It usually starts when human identities and NHIs are governed as if they are the same problem. People can be challenged with MFA, recovery checks, and session validation. Service accounts, API keys, OAuth grants, and agent credentials behave differently: they are embedded in workflows, reused by automation, and often remain valid long after the task they support has changed.
That difference is why the Ultimate Guide to NHIs warns that NHIs often outnumber human identities by 25x to 50x, while OWASP Non-Human Identity Top 10 treats secrets exposure, overprivilege, and weak lifecycle control as core weaknesses rather than edge cases. One useful NHIMG data point is that 97% of NHIs carry excessive privileges, which directly expands the blast radius of any compromise.
Security teams get into trouble when they assume one access model can simply be “applied more strictly.” In practice, many security teams encounter unauthorized machine access only after a leaked token or dormant service account has already been reused across systems.
How It Works in Practice
The practical model is to govern humans and machines through one policy architecture, but not one set of controls. Human access should still rely on MFA, phishing-resistant recovery, and session assurance. NHI access should be driven by workload identity, explicit inventory, and short-lived credentials. That means mapping every API key, token, certificate, service account, and third-party OAuth grant to an owner, purpose, and expiry.
For machine-to-machine access, current guidance suggests using runtime checks instead of static entitlement assumptions. This is where workload identity standards such as SPIFFE help establish what the workload is, while policy engines evaluate what it is allowed to do at the moment of request. That approach aligns with the NIST Zero Trust Architecture principle that trust should be continuously evaluated, not granted once and remembered forever.
Operationally, teams should enforce:
- Separate control paths for interactive users and NHIs, with a shared governance register.
- Just-in-time provisioning for privileged machine actions, with automatic revocation on task completion.
- Credential TTLs that match workload duration, not calendar convenience.
- Rotation and offboarding playbooks that cover code, CI/CD, vaults, and third-party integrations.
- Real-time authorization using policy-as-code, so access can be narrowed by environment, tool, and purpose.
Ultimate Guide to NHIs — Key Challenges and Risks notes that many organisations still store secrets in unsafe places and lack full visibility into service accounts, which is exactly why inventory is not a paperwork exercise but an enforcement control. These controls tend to break down in fast-moving CI/CD pipelines and multi-tenant SaaS integrations because credentials are issued and reused faster than owners can review them.
Common Variations and Edge Cases
Tighter machine-access control often increases operational overhead, so organisations have to balance speed against containment. That tradeoff is real: some systems need long-lived integrations, while others can move safely to short-lived tokens and just-in-time access. Best practice is evolving, but there is no universal standard for every hybrid environment yet.
Third-party access is the most common exception area. OAuth apps, managed service providers, and contractor automation frequently create access paths that do not fit neatly into a human-or-NHI split. In those cases, the rule should be the same: assign an owner, define the allowed scope, enforce review dates, and revoke anything that is unused or unverified. The 52 NHI Breaches Analysis shows that weak lifecycle control is a recurring pattern, not a one-off failure.
There are also environments where standing privilege cannot be eliminated immediately, such as legacy mainframes, embedded devices, or vendor-managed platforms. In those cases, security teams should isolate the account, restrict where it can connect, and place it under continuous monitoring until it can be refactored. The goal is not perfect symmetry between humans and machines. The goal is a single governance model that recognizes different identity types and prevents either one from becoming an unseen access path.
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 and OWASP Agentic AI Top 10 address the attack and risk surface, while 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 | Addresses lifecycle rotation and revocation of machine secrets. |
| OWASP Agentic AI Top 10 | A2 | Covers excessive tool access and misuse paths for autonomous agents. |
| NIST AI RMF | Supports governance and accountability for identity-dependent AI systems. |
Inventory NHIs, rotate credentials on schedule, and revoke unused access immediately.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on June 8, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
