Why do large enterprises need identity security for both people and machines?

Why This Matters for Security Teams

Large enterprises do not just manage user sign-ins. They manage service accounts, API keys, workloads, pipelines, bots, and agentic systems that can act faster and at greater scale than people. That is why identity security has to span both human and non-human identities, with consistent governance across NIST SP 800-53 Rev. 5 Security and Privacy Controls and the operational reality documented in Ultimate Guide to NHIs.

The practical issue is not simply volume. It is that machines and software identities are often issued credentials outside normal joiner-mover-leaver processes, then left running with excessive access and weak rotation discipline. NHIMG research shows that NHIs outnumber human identities by 25x to 50x in modern enterprises, and 97% carry excessive privileges, which means the attack surface is already dominated by access that does not belong to a person.

For security teams, the risk is fragmentation. Human IAM, cloud IAM, DevOps tooling, and third-party integrations frequently operate in separate control planes, so no one sees the full access graph. In practice, many security teams encounter machine identity abuse only after exposed secrets, over-privileged accounts, or compromised integrations have already been used to move laterally.

How It Works in Practice

A unified identity program treats every actor as an identity problem first and an asset problem second. People still need SSO, MFA, lifecycle governance, and role management. Machines need comparable controls, but expressed differently: workload identity, credential issuance, rotation, secret storage, and runtime authorization.

For human users, the baseline is well understood: strong authentication, least privilege, access reviews, and separation of duties. For non-human identities, the controls shift to service-account inventory, ownership, TTL-based credentials, and policy enforcement tied to the workload rather than to a static username. The operational goal is to know what the identity is, what it is allowed to do, who owns it, and how quickly it can be revoked.

Current best practice is evolving toward:

• central inventory of human and machine identities across cloud, SaaS, CI/CD, and production systems;
• short-lived credentials and automated rotation for secrets, keys, and tokens;
• runtime authorization based on context, not just static group membership;
• continuous monitoring for anomalous use, especially for service accounts and third-party OAuth apps;
• clear ownership and offboarding procedures for every non-human identity.

This is consistent with the control intent in NIST SP 800-53 Rev. 5, especially where access control, account management, and audit logging intersect. It also aligns with NHIMG guidance in the Ultimate Guide to NHIs, which shows how frequently secrets are stored outside dedicated managers and how often rotation fails in real environments. These controls tend to break down when development teams, cloud teams, and security teams each believe another group owns the machine identity lifecycle.

Common Variations and Edge Cases

Tighter identity control often increases operational overhead, so organisations must balance security coverage against deployment speed and developer friction.

One common edge case is third-party access. A vendor integration may authenticate with OAuth, a service account, or an API token, and each path creates different visibility gaps. Another is legacy infrastructure, where older applications cannot easily support modern workload identity and must be wrapped with compensating controls. In both cases, the security model has to be realistic rather than idealised.

There is no universal standard for this yet, especially where agentic systems, ephemeral workloads, and multi-cloud service meshes overlap. However, guidance increasingly points toward the same pattern: treat credentials as disposable, treat identities as continuously governed, and treat access as a runtime decision. That is why NHI-specific research such as 52 NHI Breaches Analysis matters. It shows that attackers repeatedly exploit the same control gaps, especially around secrets exposure and over-privileged access.

For enterprises with mixed environments, the right answer is not a separate program for people and machines. It is one identity strategy with different control patterns for each identity type, governed under a shared security model and measured continuously.

Related resources from NHI Mgmt Group

• Why do identity security programmes lose value after initial rollout in mature enterprises?
• Why does identity security become harder as enterprises adopt more applications and automation?
• Why does identity provider sprawl create security risk in large enterprises?
• Why do bring your own identity models create new trust and governance risks for security teams?