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.
Expanded Definition
Non-Human Identity, or NHI, is the identity layer used by software, services, bots, machines, workloads, and AI agents to prove who or what they are to another system. In practice, an NHI is not the workload itself; it is the credentialed identity, trust relationship, or tokened account that lets the workload authenticate, authorize, and act. That distinction matters because the same application can hold multiple identities across environments, tenants, and toolchains.
Definitions vary across vendors and programmes on whether to treat API keys, certificates, service accounts, and agent credentials as separate classes or as one NHI umbrella. For practitioners, the useful boundary is operational: if the entity is not human but can obtain access, assume lifecycle and governance obligations still apply. The OWASP Non-Human Identity Top 10 is a helpful reference point because it frames NHI as a distinct security problem set rather than a subset of human IAM.
A common misunderstanding is to equate NHI only with service accounts. In reality, machine identities can be embedded in CI/CD, cloud workloads, integrations, and autonomous agents, which broadens the trust boundary well beyond classic directory accounts.
Examples and Use Cases
NHI shows up anywhere systems must authenticate without a person typing a password or approving a prompt. The exact form changes, but the security problem is similar: an identity must be issued, scoped, monitored, rotated, and eventually removed.
- A microservice uses a workload identity to call a payment or data service inside a zero-trust architecture.
- A CI/CD pipeline stores a deployment token so automation can push code, sign artifacts, or update cloud resources.
- A SaaS integration uses an API key or OAuth token to move data between ticketing, logging, or analytics platforms.
- An AI agent uses tool credentials to query internal systems, open tickets, or execute actions on behalf of a user or workflow.
- A certificate-backed machine identity authenticates an IoT device, container, or edge service to a central platform.
Implementation tradeoff often appears in convenience versus control. The more easily an NHI can be reused across systems, the harder it becomes to prove ownership, limit scope, and trace which workload actually used the credential.
Security Implications
NHI becomes risky when organisations treat machine access as permanent infrastructure instead of managed identity. That usually leads to overprivileged credentials, hard-coded secrets, weak inventory, and unclear ownership. When a machine credential is exposed, the attacker does not need a human to log in, which makes misuse fast and difficult to distinguish from normal automation.
NHIMG research shows the scale of the problem: 97% of NHIs carry excessive privileges, increasing unauthorised access and broadening the attack surface. That matters because excessive scope turns a single leaked token, key, or certificate into broad system reach rather than a narrow failure.
Operational symptoms are often subtle. Teams may see service disruption after rotation, broken automation after offboarding, or unexplained access from a valid credential that was never revoked. In many environments, the hardest part is not initial authentication, but proving which non-human identities still exist, which ones are active, and which ones should no longer be trusted.
Domain and Governance Relevance
NHI is central to modern identity governance because non-human access now spans cloud, DevOps, API integration, and autonomous execution. This changes governance from periodic human joiner-mover-leaver processes into continuous lifecycle control for accounts, secrets, certificates, and tokens that may never have a human owner in the traditional sense.
For NHI security, the key governance question is whether each identity has a named owner, a clear business purpose, a limited trust scope, and an explicit retirement path. That is especially important where NHIs outnumber human identities by 25x to 50x, because scale makes manual tracking unreliable and hidden access paths easy to miss.
In practice, NHI governance also affects Zero Trust adoption, third-party access, and agentic AI controls. If a workload or agent can act independently, its identity becomes part of the organisation’s trust fabric, not just an implementation detail. For that reason, NHI should be managed as a first-class identity class with the same seriousness as privileged human access, but with lifecycle rules designed for automation rather than people.
Risk and Threat Considerations
NHI creates concentrated exposure because machine credentials are often long-lived, widely reused, and embedded in automation that rarely pauses for review. The risk is not only theft; it is also unnoticed persistence, where a valid token or service account remains trusted long after the workload, project, or vendor relationship should have ended.
Failure mechanism: Weak inventory, overbroad privilege, hard-coded secrets, and delayed revocation let attackers abuse legitimate NHI trust rather than bypass it. Once a credential is captured, the attacker can often authenticate as the machine, blend into normal service traffic, and move through connected systems without triggering human-login based controls.
Impact: The result can be data exposure, service impersonation, lateral movement, supply-chain reach, or loss of control over automated actions. In agentic environments, compromise can also turn a machine identity into an execution path for repeated, autonomous abuse.
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 CIS Controls v8 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-01 — Inventory and Ownership | Defines machine identities that need clear ownership and lifecycle control. |
| NHI-02 — Secrets and Credential Management | Covers API keys, tokens, certificates, and other machine credentials. | |
| NHI-04 — Privilege and Access Boundaries | Addresses excessive privilege and overbroad machine access paths. | |
| Recommendation — Inventory every NHI and assign an accountable owner for each identity. Protect NHI credentials with vaulting, rotation, and tight access scope. Constrain each NHI to the minimum permissions its workload actually needs. | ||
| CIS Controls v8 | CIS-05 — Account Management | Maps to lifecycle control for non-human accounts and service identities. |
| CIS-16 — Application Software Security | Applies where NHI secrets are embedded in code, CI/CD, or app workflows. | |
| Recommendation — Track NHI accounts continuously and remove stale or orphaned access promptly. Keep secrets out of code and build pipelines to reduce NHI exposure. | ||
| NIST Zero Trust (SP 800-207) | PR.AC-1 — Identity and Credential Assurance | Zero Trust depends on trustworthy machine identity and credential validation. |
| PR.AC-4 — Access Permissions | Zero Trust limits machine access through least-privilege policy enforcement. | |
| Recommendation — Require strong identity assurance before granting any NHI access path. Enforce least-privilege access for every machine and agent identity. | ||
| MITRE ATT&CK | T1552 — Unsecured Credentials | Covers attacker discovery and abuse of exposed secrets and tokens. |
| Recommendation — Hunt for exposed NHI secrets in code, logs, tickets, and shared tools. | ||
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 7, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
