Inventory AI agents by owner, delegated authority, runtime accounts, tool connections, data scopes, and every certificate, token, or key they use. For post-quantum migration, map which agents depend on RSA, ECC, or TLS certificates, then classify them by replacement urgency and dependency chain. Include scheduled jobs, backup agents, and human approvers so revocation and rollover can be planned without losing control.
What to inventory beyond the agent name
For post-quantum migration, the useful inventory is not just a list of “agents,” but a map of everything they depend on to act. That means recording the owner, delegated authority, runtime account, tool chain, data scopes, and the cryptographic material that actually binds trust, including certificates, tokens, and keys. A certificate lifecycle view is especially important when agents rely on TLS or X.509, because migration decisions often follow dependency chains rather than the agent itself. Machine Identity, PKI and Certificate Lifecycle Guide
Teams should also include scheduled jobs, backup automation, and human approvers in the same inventory because they can preserve or revoke authority when an agent is changed, replaced, or retired. If those supporting actors are omitted, the migration plan may look complete while hidden control paths still keep the old trust model alive.
When the same agent has multiple tool connections or multiple data scopes, split those dependencies rather than treating them as one record. That makes it easier to see which parts are tied to sensitive production data, which are merely operational, and which can be migrated first without blocking the whole estate.
How to classify agent dependencies for PQC migration
The most practical classification is by cryptographic dependency and replacement urgency. Start by identifying which agents depend on RSA, ECC, or TLS certificates, then rank them by how directly those dependencies affect runtime access, external connectivity, or signed trust decisions. Agents that authenticate to production systems, call external services, or present certificates on a live path should usually move ahead of offline or low-frequency workflows.
It also helps to classify by dependency chain, not only by algorithm. An agent may not use RSA directly, but it may rely on a service account, gateway, or certificate authority flow that does. In that case, the migration work belongs to the chain, because the weakest link determines whether the agent can continue operating after cryptographic changes.
Agentic AI Identity Guide is useful here because it frames delegation, registration, authentication, and retirement as a lifecycle, not a one-time setup. That lifecycle view is what lets teams decide whether an agent can be reissued, rekeyed, or re-authorized without breaking the business process it supports.
For teams with many agents, classification should also separate direct trust from indirect trust. A direct trust dependency is one where the agent itself holds the credential or certificate. An indirect trust dependency is where the agent can reach the same authority through another runtime, gateway, or shared integration point. Those indirect paths are often where migration surprises surface.
Planning rollover without losing control
The inventory becomes operationally useful only when it supports rollover planning. That means documenting who can approve rotation, which systems need dual trust during transition, and which agents must be paused if the old credential family is withdrawn. Without that, teams tend to discover that revocation is technically possible but operationally unsafe.
AI Agent Authorisation Guide is a good companion here because it treats per-action policy, delegated authority, and human approval as part of the control plane. For PQC migration, that matters because some agents will need temporary exceptions, staged cutovers, or narrower authority while certificate and key changes are being tested.
Migration planning should distinguish between “must replace” and “can defer.” A long-lived token or certificate on a high-value agent is not just a technical asset, it is a migration constraint. If the inventory cannot show where those credentials are used, revocation plans will be incomplete and the team may be forced to keep legacy algorithms longer than intended.
Risk and Threat Considerations
AI agent inventories become risky when they are incomplete, because the missing item is often the one that still holds the live trust relationship. In a post-quantum programme, that can leave RSA or ECC dependencies hidden in unattended jobs, integration accounts, or backup paths, where they survive longer than the primary system.
Failure mechanism: An agent keeps working through an untracked certificate, token, or delegated account after the main migration path has been updated, so legacy cryptography remains in production and the organisation cannot revoke or replace it safely.
Impact: The result is delayed quantum-readiness, accidental service disruption during rollover, and a larger compromise surface if the old trust path is abused before it is removed.
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 addresses the attack and risk surface, while NIST SP 800-53 Rev 5 and NIST SP 800-57 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-02 — Secret Leakage | Agent inventories must include tokens, keys, and certificates used by agents. |
| NHI-07 — Long-Lived Secrets | PQC migration is constrained by long-lived certificates, tokens, and keys. | |
| Recommendation — Catalog every agent secret and rotate exposed material before cutting over trust paths. Prioritise renewal and replacement of long-lived agent credentials first. | ||
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | The question centers on lifecycle control of agent credentials and certificates. |
| IA-9 — Service Identification and Authentication | AI agents authenticate as non-human services through runtime accounts and certificates. | |
| AC-6 — Least Privilege | Delegated authority and tool access determine migration blast radius. | |
| Recommendation — Track, rotate, and revoke agent authenticators on a managed lifecycle. Inventory service authenticators used by agents and verify their trust chains. Reduce each agent to the minimum access needed before migrating credentials. | ||
| NIST SP 800-57 | 3.1 — Cryptographic Key Lifecycle Management | Migration depends on replacing RSA, ECC, and certificate-backed trust with new key lifecycles. |
| Recommendation — Map key lifecycles and schedule replacement before legacy algorithms must be removed. | ||
Practitioner Guidance
What to verify: Make sure each agent record ties to a specific runtime identity and not just a business label. If the record cannot answer “what credential does this agent actually present to which system,” it is not ready for migration planning.
Implementation sequence: Inventory the agent, map every certificate and key it depends on, identify the downstream systems that trust it, then order remediation by live exposure first, batch jobs second, and dormant dependencies last.
Practitioner takeaway: Treat post-quantum inventory as a dependency and revocation problem, not a naming exercise, because migration succeeds only when you can replace trust without losing operational control.
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Reviewed and updated by the NHIMG editorial team on November 6, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org