Choose based on the identity type being governed. Password managers are designed primarily for human credentials, while secret managers and adjacent vault controls are more relevant for API keys, tokens, certificates, and service accounts. Many enterprises need both patterns, with different ownership, rotation, and offboarding rules for each.
Why This Matters for Security Teams
The choice is not really about tooling preference. It is about whether the team is governing a human credential or a machine credential, because those identities fail in different ways and require different lifecycle controls. Password managers help reduce human reuse and phishing risk, while secret managers are built for API keys, certificates, tokens, and service accounts that need rotation, access boundaries, and automated revocation.
This distinction matters because secrets sprawl creates a broader attack surface than many teams expect. NHI Management Group notes that 96% of organisations store secrets outside of secrets managers in vulnerable locations, and 79% have experienced secrets leaks with tangible damage in most incidents. That pattern is visible in supply chain incidents, CI/CD compromise, and lateral movement after one credential is exposed, as seen in cases discussed in the Guide to the Secret Sprawl Challenge and the Shai Hulud npm malware campaign.
Security teams that treat both categories as interchangeable usually discover the gap only after a credential has already been embedded in code, shared through a ticket, or inherited by a service account no one owns. In practice, many security teams encounter secret exposure only after the workload has already been compromised, rather than through intentional control design.
How It Works in Practice
Start by classifying the identity before choosing the control. If the credential is used by a person to sign in interactively, a password manager is usually the right fit. If the credential is used by software, automation, or infrastructure, a secret manager or adjacent vault control is the safer default. This aligns with the direction reflected in the OWASP Non-Human Identity Top 10 and the NIST Cybersecurity Framework 2.0, which both emphasize governance, access control, and lifecycle discipline.
Operationally, the control model should follow the identity lifecycle, not the convenience of the storage layer. For machine identities, best practice is evolving toward short-lived credentials, scoped access, and automatic rotation tied to workload context. The most effective programs usually combine:
- human password vaulting for interactive accounts, with phishing-resistant authentication and recovery controls
- secret managers for API keys, tokens, certificates, and service account material
- ownership tags so every secret has a named system or team accountable for rotation and revocation
- automatic expiry or renewal so credentials do not live longer than the workload that uses them
- offboarding workflows that revoke access when a service, pipeline, or integration is retired
For NHIs, the stronger pattern is to reduce static secret wherever possible and replace them with workload identity, ephemeral tokens, or brokered access. That is the direction described in Ultimate Guide to NHIs – Lifecycle Processes for Managing NHIs and NHI Lifecycle Management Guide, because the real control objective is not just storage, but issuance, use, rotation, and revocation under policy.
These controls tend to break down when secrets are hard-coded into CI/CD systems or shared across many automated jobs, because the access path becomes too broad and too persistent for meaningful containment.
Common Variations and Edge Cases
Tighter secret governance often increases operational overhead, so organisations have to balance usability against blast-radius reduction. That tradeoff is most visible in legacy environments, where teams may still need a password manager for administrator access while separately using a vault for production integrations and build pipelines.
One common edge case is a hybrid credential model: a human provisions a machine credential, but the machine uses it unattended. In that case, the storage tool alone is not the answer. The team needs policy on creation, TTL, rotation, and revocation, plus monitoring that can spot drift or orphaned secrets. Another edge case is third-party access. OAuth apps, vendor integrations, and managed services often bypass normal password workflows, which is why current guidance suggests treating them as NHIs even when a human originally approved them.
There is no universal standard for this yet, but the safest operational rule is simple: if the identity authenticates a person, favour password manager controls; if it authenticates software, favour secret manager controls and workload identity. For deeper context on how secrets escape normal controls, see the Top 10 NHI Issues. When teams blur the two models, they usually lose visibility first and revocation last.
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 | Addresses secret rotation and lifecycle gaps for machine identities. |
| NIST CSF 2.0 | PR.AC-4 | Supports least-privilege access management for human and non-human identities. |
| NIST AI RMF | Helps govern autonomous or automated systems that rely on secrets and service accounts. |
Assign ownership, monitor usage, and manage credential risk across the full AI system lifecycle.
Related resources from NHI Mgmt Group
- How should security teams choose between a cloud secret store and broader access governance?
- How should security teams handle browser-specific failures in password manager extensions?
- Why do password managers improve security without removing password risk?
- How should security teams decide whether JIT access is safe for non-human identities?
