Because the organisation can authenticate users successfully while losing track of the devices themselves. When keys are not centrally assigned, inventoried, and retired, they become long-lived trust anchors that outlive role changes and offboarding. The risk is not the key format, but the absence of lifecycle control.
Why This Matters for Security Teams
Hardware keys are often treated as a strong authentication factor, but governance breaks down when the organisation cannot prove who owns each key, where it is used, or when it should be retired. That creates a false sense of assurance: login still works, yet the trust anchor may belong to someone who changed roles, left the company, or no longer needs access. NHI Management Group’s lifecycle guidance emphasises that identity controls fail when assignment and retirement are not operationalised, not when the token is merely physical.
This is why weak lifecycle management becomes a governance problem, not just an endpoint problem. A key that is never inventoried or revoked can outlive access reviews, joiner-mover-leaver workflows, and even device refresh cycles. The issue is especially visible in audit and incident response, where teams discover that authentication succeeded long after the business relationship should have ended. Current guidance in the NHI Lifecycle Management Guide and the NIST Cybersecurity Framework 2.0 points toward the same operational reality: identity assurance depends on lifecycle control, not just strong credentials. In practice, many security teams discover orphaned hardware keys only after a departure review or breach investigation, rather than through intentional inventory discipline.
How It Works in Practice
Governance starts with treating every hardware key as an owned asset with a lifecycle record, not a standalone authenticator. That record should tie the key to a named user, a business purpose, an issuance date, an expected expiry or replacement date, and a revocation path. When this is done well, the organisation can answer three questions at any time: who has the key, what systems it can access, and whether it is still valid for the current job role.
In operational terms, strong lifecycle management usually includes:
- central issuance and registration before a key is trusted for access
- continuous inventory that maps keys to people, devices, and privileged applications
- clear offboarding triggers so lost, retired, or reassigned keys are revoked promptly
- periodic attestations that confirm the key still matches the user’s current role
- replacement and recovery procedures that do not create duplicate active trust anchors
That approach aligns with the risks highlighted in Top 10 NHI Issues and the attack patterns discussed in OWASP Non-Human Identity Top 10, where unmanaged credentials remain active longer than intended. It also matches the evidence in NHIMG research that credential rotation and lifecycle discipline are central weaknesses, with former employee tokens often remaining active after offboarding. The practical lesson is simple: the stronger the authenticator, the more damaging it becomes when inventory, ownership, and retirement are weak. These controls tend to break down in decentralised environments where keys are issued by multiple teams, because no single system can enforce retirement consistently.
Common Variations and Edge Cases
Tighter hardware-key governance often increases operational overhead, requiring organisations to balance stronger assurance against user friction and support complexity. That tradeoff is real, especially where contractors, shared workstations, emergency access, or remote staff need rapid access without long approval chains.
Best practice is evolving for these edge cases. Some organisations issue separate keys for privileged and standard access, while others use short approval windows and rapid re-issuance when a key is lost or replaced. There is no universal standard for this yet, but the direction is consistent: lifecycle controls should be stricter for privileged access and more automated for high-churn populations. The Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs and Guide to NHI Rotation Challenges both reinforce that rotation, retirement, and ownership tracking must be designed together, not added later.
Another edge case appears when keys are used for both human authentication and operational signing workflows. In that scenario, the key may remain technically valid while its business purpose has changed, which complicates revocation decisions. The right control is not just disabling the key on schedule, but proving that its current use still matches the approved trust boundary. When organisations fail to do that, hardware keys become durable exceptions that outlive the governance model they were supposed to enforce.
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 CSA MAESTRO 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 | Covers lifecycle control gaps that leave keys active after ownership changes. |
| NIST CSF 2.0 | PR.AC-1 | Access control depends on knowing who is authorised and when access should end. |
| NIST AI RMF | Governance requires accountable lifecycle processes for identity-bearing assets. | |
| CSA MAESTRO | M1 | Agentic and workload governance both need strong identity lifecycle discipline. |
Assign ownership, monitoring, and retirement duties for every hardware key under an AI RMF governance model.
