By NHI Mgmt Group Editorial TeamBased on P0 Security: “Non-Human Identities (NHIs) vs. Machine Identities: Key Differences & Security Best Practices” (August 26, 2025)

TL;DR: P0 Security argues that NHIs are broader than machine identities, spanning service accounts, API keys, tokens, certificates, bots, and even legal entities, so treating them as one category misaligns discovery, least privilege, rotation, and monitoring with real exposure paths. The control model has to follow identity type, not shorthand labels.


At a glance

What this is: This article explains why non-human identities are a broader governance category than machine identities and shows where security controls diverge across scope, management, and risk.

Why it matters: IAM, IGA, PAM, and NHI programmes need distinct control patterns for service accounts, API keys, tokens, certificates, and other non-human identities, or lifecycle and privilege controls will miss the real exposure paths.

👉 Read P0 Security's analysis of non-human identities vs machine identities


Context

Non-human identity governance fails when teams treat every machine-related credential as if it belongs to the same control bucket. NHIs include service accounts, bots, API keys, tokens, certificates, devices, and even legal entities, so discovery, ownership, and deprovisioning need to reflect the identity type rather than a generic label.

The practical problem is not abstraction. Security teams often secure workloads and devices well enough while leaving service accounts, application credentials, and other non-human identities governed by different, weaker lifecycle rules. That creates blind spots in inventory, privilege assignment, and monitoring.

The article’s core point is that machine identities are only one subset of NHI governance, so programme design has to start with classification before control selection. Without that, organisations end up applying the wrong management pattern to the wrong identity class.


Key questions

Q: What breaks when organisations treat all non-human identities as the same thing?

A: Controls break because different NHIs require different lifecycle, privilege, and monitoring patterns. A service account, a workload certificate, and an API key do not fail in the same way, so a one-size policy can leave stale access, duplicated secrets, or overprivileged automation in place. The result is tidy policy language and messy execution.

Q: What problem does ownership attribution solve for service accounts and API keys?

A: It closes the gap between exposure detection and accountable remediation. Many organisations can find the secret, but not the human who introduced it, maintains it, or can safely replace it. Ownership attribution gives security teams a practical way to assign action without relying on informal knowledge that disappears during staff changes.

Q: How should security teams prioritise non-human identity remediation?

A: Prioritise the identities with the largest blast radius first. That usually means service accounts or tokens that can write to production, cross trust boundaries, or reach sensitive data. A useful programme ranks remediation by effective permissions and business impact, not by how many identities exist or how old the finding looks.

Q: When does machine identity management miss broader NHI risk?

A: It fails when the programme only tracks workloads and certificates while ignoring the rest of the non-human estate. That leaves bots, service accounts, and other machine-adjacent identities outside the lifecycle and monitoring model, even though they can still be abused for access and persistence.


Technical breakdown

Why machine identities are only one NHI subset

Non-human identities are a broad governance category that includes devices, applications, automated processes, and legal entities. Machine identities are narrower: they usually refer to workloads, devices, and cloud services authenticated with X.509 certificates or cryptographic keys. The distinction matters because the attack surface and operating model differ. A service account or API key is managed through credential lifecycle controls, while a machine identity often hinges on certificate issuance, trust anchors, and workload-to-workload authentication. If teams collapse those categories, they miss different inventory, rotation, and revocation requirements.

Practical implication: Map each non-human identity class to its own ownership, credential, and lifecycle controls instead of using a single NHI process.

Why discovery and inventory fail when identity scope is blurred

Discovery only works when the organisation knows what it is trying to find. If the programme searches for “machine identities” alone, it can overlook service accounts, bots, API keys, and other non-human identities that do not behave like workload certificates. That creates partial inventories and weak deprovisioning, especially when identities are embedded in automation or spread across cloud and on-premises systems. Governance breaks down when the inventory model is narrower than the operating reality. Accurate scoping is the prerequisite for any meaningful NHI security baseline.

Practical implication: Build inventory logic that separates workloads, service accounts, API credentials, and other NHI classes before governance decisions are made.

How credential management changes across NHI types

Credential strategy differs by identity type. Machine identities often rely on certificates and cryptographic keys, while other NHIs may use passwords, tokens, or API keys. That changes the control objective: some identities need certificate lifecycle discipline, while others need secret storage, rotation, and revocation workflows. The common mistake is assuming one rotation model fits all non-human identities. It does not. The right control is the one that matches the credential form, the authentication flow, and the blast radius if the identity is abused.

Practical implication: Align rotation and revocation controls to the credential type in use, not to the broad label of the identity.


Threat narrative

Attacker objective: The objective is to use a misclassified or poorly governed non-human identity to gain unauthorised access and expand the reachable environment.

  1. Entry begins when a stale service account, exposed API key, or other unmanaged non-human identity can be used outside its intended lifecycle.
  2. Escalation occurs when the identity has more scope than the task requires, letting an attacker or abuse case move from access to broader privilege.
  3. Impact follows when the wrong NHI class is governed as if it were a machine identity, leaving credential misuse, unauthorized communication, or compliance exposure undetected.
  • Dropbox Sign breach 2024: A compromised back-end service account gave attackers Dropbox Sign customer data, including API keys, OAuth tokens and MFA information.
  • Coupang Signing Key Breach: Unrevoked signing key credentials expose 33.7 million records after employee offboarding failure at Coupang.

Read and download The State of NHI & AI Agent Breach Report 2026, covering 150+ breaches impacting Non-Human Identities including AI Agents.


NHI Mgmt Group analysis

Classification is the first control decision in NHI governance. This article reinforces a basic truth that many programmes still miss: machine identities are a subset of NHIs, not a synonym for the whole category. If service accounts, bots, API keys, and legal entities are collapsed into one bucket, control design becomes inconsistent and ownership becomes unclear. The practitioner takeaway is simple: identity type must drive governance pattern.

Discovery models fail when they are scoped too narrowly. A programme that only inventories workload-style machine identities will miss other NHI classes that create real exposure, especially embedded automation and service credentials. That is not a tooling issue alone; it is a classification problem. The implication is that inventory and recertification processes must be built around the full NHI taxonomy, not just the most visible subset.

Credential form changes the governance problem. Certificates, keys, tokens, and passwords do not fail in the same way, so lifecycle rules cannot be copy-pasted across all non-human identities. The control logic for machine identities is different from the control logic for API keys or service accounts. Practitioners should align lifecycle, rotation, and monitoring to the actual credential mechanism in use.

Misclassification creates identity blast radius. When an organisation treats a broad NHI estate as if it were only a machine identity problem, it underestimates where privilege, persistence, and unauthorized communication can emerge. That is why NHI programmes need explicit ownership, naming, and offboarding rules for each identity class. The practitioner conclusion is to govern by exposure path, not by convenience.

Identity governance for NHIs is becoming an operating model question, not a point-control question. The article points to a future where discovery, lifecycle, and monitoring need to be unified across identity classes while still preserving type-specific controls. That is the direction mature NHI governance is heading: one programme, multiple control patterns, and no assumption that machine identity tooling alone solves the full problem. Practitioners should design for classification first and enforcement second.

From our research library:

What this signals

Identity programmes need a taxonomy before they need another control. The biggest operational risk in this topic is not the existence of machine identities, but the tendency to govern every non-human identity with the same policy. Once the taxonomy is explicit, lifecycle ownership, credential form, and monitoring can be mapped cleanly to the right control pattern.

NHI blast radius starts with misclassification. When service accounts, API keys, and machine identities are collapsed into one operational bucket, teams usually overestimate coverage and underestimate persistence. That is exactly where identity drift begins, and it is why classification belongs at the front of the governance process, not as a reporting afterthought.


For practitioners

  • Define an NHI taxonomy before tooling Separate machine identities, service accounts, API keys, tokens, bots, devices, and other non-human identities into distinct governance classes with assigned owners.
  • Inventory identities by credential type Build discovery routines that find certificates, keys, passwords, and tokens independently so the inventory reflects how each identity is authenticated.
  • Assign lifecycle ownership to every NHI class Require a named owner for provisioning, monitoring, rotation, and deprovisioning of each non-human identity category, including service accounts and automation credentials.
  • Match monitoring to the actual identity type Use different detection logic for machine-to-machine certificates, service account usage, and API key activity so anomaly detection follows the real access pattern.
  • Review least privilege at the credential layer Verify that the permissions attached to each non-human identity match the task it performs, especially where tokens or keys are reused across environments.

Key takeaways

  • Machine identities are only one part of the broader NHI problem, so governance has to distinguish identity classes before controls are assigned.
  • A single NHI policy is too blunt for service accounts, API keys, tokens, certificates, and automation credentials because their lifecycle and exposure paths differ.
  • The practical answer is taxonomy-driven governance: classify, inventory, assign ownership, and then apply the right credential and monitoring model.

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 MITRE ATT&CK address the attack and risk surface, while NIST CSF 2.0 and NIST SP 800-53 Rev 5 set the governance and control requirements practitioners need to meet.

FrameworkControl / ReferenceRelevance
OWASP Non-Human Identity Top 10NHI-05 — Overprivileged NHIThe article warns that broad NHI handling hides over-scoped machine and service identities.
NHI-01 — Improper OffboardingThe article stresses deprovisioning and lifecycle ownership for non-human identities.
Recommendation — Map each NHI class to its own privilege model and reduce any identity whose access exceeds task scope. Tie every NHI class to an explicit offboarding path so dormant identities are removed when no longer needed.
NIST CSF 2.0PR.AA-05 — Access Permissions, Entitlements and AuthorizationsThe core issue is matching permissions and entitlements to each non-human identity type.
Recommendation — Review NHI entitlements against actual business function and remove permissions that are not required.
NIST SP 800-53 Rev 5IA-5 — Authenticator ManagementThe article discusses rotating and managing keys, tokens, and other authenticators across NHI types.
Recommendation — Apply authenticator management to rotate, store, and revoke NHI credentials according to their credential type.
MITRE ATT&CKTA0006;TA0008 — Credential Access; Lateral MovementThe breach patterns referenced show how exposed non-human credentials lead to access and expansion.
Recommendation — Track exposed NHI credentials to credential-access and lateral-movement tactics in your detection content.

Key terms

  • Non-Human Identity (NHI): A digital identity assigned to a non-human entity such as a software application, service account, API key, bot, machine, or AI agent that enables it to authenticate and interact with systems without direct human involvement. NHIs now outnumber human identities in most enterprises by 25 to 50 times.
  • Machine Identity: The digital identity of a machine, device, or workload, such as a server, container, or VM, used to authenticate it within a network. Sometimes used interchangeably with NHI, though NHI is the broader category.
  • NHI Classification: NHI classification is the process of identifying what a non-human credential belongs to, what it can access, and who owns its lifecycle. Without classification, teams cannot reliably decide whether a token is a benign test value, a valid workload identity, or an exposed credential that needs immediate action.
  • Credential Lifecycle: Credential lifecycle is the process of issuing, rotating, expiring, and revoking secrets, certificates, and tokens across their usable life. For non-human identities, lifecycle discipline is the core control that separates temporary access from persistent exposure.

What's in the full article

P0 Security's full article covers the operational detail this post intentionally leaves for the source:

  • A side-by-side breakdown of how machine identities, service accounts, legal entities, and automation credentials differ in practice.
  • The article’s own best-practice sequence for discovery, centralised management, privilege control, authentication, and monitoring.
  • Examples of how to distinguish machine identity security from broader NHI governance when writing policy or designing controls.
  • The FAQ section’s concise answers on the biggest NHI risks and how to prioritise controls.

👉 P0 Security's full article expands the governance distinctions, best-practice sequence, and FAQ guidance for NHI security.

Deepen your knowledge

NHI governance, agentic AI identity, and machine identity security are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building or maturing an IAM programme, it is worth exploring.
NHIMG Editorial Note
Published by the NHIMG editorial team on June 24, 2026.
Updated on October 8, 2026.
NHI Mgmt Group, the independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org