Who should own Zero Trust governance across human and machine identities?

Why This Matters for Security Teams

zero trust governance fails when human identity controls and machine identity controls are split across separate owners, because the policy decisions, exception handling, and lifecycle events all intersect at the same access boundary. Security teams usually discover the gap after a service account, API key, or workload identity has been over-privileged long enough to become an incident path. That is why the operating model matters as much as the technology stack. NIST’s Cybersecurity Framework 2.0 and SP 800-207 both point toward governance that unifies identity, policy, and trust decisions instead of treating them as isolated tasks. NHIMG research shows the operational stakes are already visible: only 1.5 out of 10 organisations are highly confident in their ability to secure non-human identities, compared with nearly 1 in 4 for human identities, according to The State of Non-Human Identity Security. In practice, many security teams encounter this mismatch only after a workload compromise or access review failure has already exposed the governance split, rather than through intentional design.

How It Works in Practice

The most workable model is shared governance with clear decision rights. IAM typically owns identity standards, authentication patterns, and entitlement lifecycle. Security architecture owns the Zero Trust policy model, trust boundaries, and exception criteria. Identity operations handles provisioning, rotation, and deprovisioning. For machine identities, that structure must also include workload identity and short-lived credentials, not just user-style access records. NHIMG’s Guide to SPIFFE and SPIRE is a useful reference point because workload identity gives teams a cryptographic way to prove what a workload is before it is authorised to act. A practical governance model usually includes:

• one policy owner for Zero Trust rules and exceptions;
• one lifecycle owner for service accounts, secrets, and certificates;
• one review cadence for both human and machine privileges;
• one control path for emergency elevation and rapid revocation.

Best practice is evolving toward policy as code, so access decisions are evaluated at request time using context, not only at onboarding. That matters because machine identities often need JIT credentials, narrow TTLs, and automatic revocation after the task completes. For this reason, the lifecycle guidance in NHIMG’s Ultimate Guide to NHIs pairs well with the governance language in NIST CSF 2.0. The key is to treat access policy, identity hygiene, and exception tracking as one operating programme. These controls tend to break down when cloud teams, platform teams, and app owners each manage a different slice of the same service account estate because no one owns the full trust chain.

Common Variations and Edge Cases

Tighter Zero Trust governance often increases coordination overhead, requiring organisations to balance speed of delivery against control consistency. That tradeoff is especially visible in platform engineering, M&A integration, and legacy application estates where service accounts were created before modern identity governance existed. In those environments, current guidance suggests assigning a single accountable owner for policy while allowing distributed execution across IAM, security, and operations. The edge cases are usually not philosophical, they are operational. Shared service accounts, long-lived API tokens, and break-glass access can all bypass normal review flows unless they are explicitly brought under the same governance umbrella. There is no universal standard for this yet, but the direction is consistent: human and machine identities should be reviewed together wherever they influence the same application, cloud, or data access path. NHIMG’s Top 10 NHI Issues highlights how credential sprawl and poor lifecycle control become governance failures, not just technical ones. For audit and reporting, NHIMG’s Regulatory and Audit Perspectives is the most relevant reference. The practical rule is simple: if a team can create access, approve access, and renew access without a shared policy owner, Zero Trust governance is already fragmented.

Related resources from NHI Mgmt Group

• Who should own least privilege governance across humans and non-human identities?
• Who should own least privilege when human and machine identities both use sensitive access?
• How should security teams implement zero trust IAM across human and machine identities?
• Who should own a unified governance model for human and non-human identities?