Key Takeaways
Machine identities are digital identities assigned to software, devices, and workloads so they can authenticate to other systems. Their credentials include TLS certificates, cryptographic keys, tokens, and cloud workload credentials.
Unlike employees, machines have no HR record or automatic leaver event. When a person resigns, HR starts an off-boarding process. A certificate issued for a migration in 2022 may have no equivalent trigger, so it remains valid until it expires or someone notices it.
That gap used to be manageable. Now it's getting expensive. The maximum lifetime of publicly trusted TLS certificates is falling on a published schedule, and every reduction increases the number of renewals teams must execute correctly.
- Machine identities often lack reliable retirement triggers, making discovery, ownership, and lifecycle management as important as issuance.
- Non-human identity is the broader category; machine identities sit within it, although the market often uses the terms interchangeably.
- Publicly trusted TLS subscriber certificates are capped at 200 days for certificates issued from March 15, 2026, falling to 100 days from March 15, 2027, and 47 days from March 15, 2029. Manual renewal has a shelf life.
- Risk concentrates at the seams of hybrid environments, where one system issues a credential, another trusts it, and no shared inventory records the relationship.
- An inventory that cannot name an owner for each machine identity cannot support confident revocation when it matters.
What Are Machine Identities?
Machine identities authenticate non-human actors: servers, containers, scripts, build pipelines, devices, and the workloads that call APIs on their own schedule. A digital certificate binds a public key to a name, and a certificate authority signs that binding so a relying party can verify it.
The verification is mechanical. A client opening a TLS connection walks the signature chain to a trusted root, confirms the name matches, and checks the validity window. Nothing in that exchange asks who owns the service or whether the service should still be running.
Public key infrastructure answers one question: whether this key belongs to this name. It answers the same way on day one and on day nine hundred.
Human identity systems work differently because they hang on employment events. Identity lifecycle management for people runs on joiner, mover, and leaver triggers fed from an HR system of record. A machine identity has a joiner event, sometimes a mover event, and no leaver event at all.
Consider an internal TLS certificate issued in 2023 for a reporting service that a team decommissioned a year later. The DNS record still resolves, the certificate still validates, and the private key still sits on a host image that three other services were cloned from.
Common Machine Identity Types and Credentials
A certificate-management tool covers one credential class, not the full machine identity category. Machine credentials come from different issuers, rotate through different processes, and often live in separate inventories.
| Credential type | What it authenticates | Typical lifetime | Where it usually lives |
|---|---|---|---|
| TLS certificates | A service to connecting clients | Up to 200 days for publicly trusted certificates; private CAs set their own limits | Load balancers, ingress controllers, API endpoints |
| SSH key pairs | A client connecting to a host | No built-in expiry | Developer devices, CI runners, bastion hosts |
| API key or static token | An application connecting to a service | Issuer-defined and sometimes non-expiring | Config files, environment variables, secret stores |
| Cloud-workload identity | A workload connecting to a cloud-control plane | Usually minutes to hours per session | Cloud IAM roles and federated trust policies |
| Kubernetes service-account token | A pod connecting to the Kubernetes API | Short-lived when issued through the TokenRequest API | Projected volumes mounted into pods |
Where lifecycle breaks down
A cryptographic key used for SSH has no expiry field of its own. If someone copies it from a repository, the host cannot distinguish the attacker from the legitimate pipeline until the key is removed.
Kubernetes has moved away from automatically creating long-lived Secret-based tokens for every service account. Current deployments can use short-lived, rotating tokens through the TokenRequest API, but older static tokens may remain in upgraded environments and should be inventoried explicitly.
AI agents generally authenticate with the same credential types, so they inherit the existing inventory problem rather than creating an entirely new one.
Location matters as much as credential type. A secrets management platform may hold API keys, PKI systems track certificates, and cloud providers store workload trust policies. Without a shared identity layer, those inventories may have no reliable way to connect a credential to its workload and owner.
Machine Identities vs. Non-Human Identities
Non-human identity is typically the broader category, covering any identity not operated directly by a person. Machine identities sit within it, although the industry does not apply the boundary consistently.
For practical program scoping, separate two groups:
- Infrastructure-issued identities: TLS certificates, SSH keys, and cloud workload identities generally managed by infrastructure and platform teams.
- Application-issued identities: OAuth grants, integration tokens, service accounts, and robotic process automation accounts often created through business applications without infrastructure involvement.
The distinction matters because ownership follows the issuing system. A certificate-and-key program can build a defensible inventory and still miss the OAuth grant a sales engineer approved last spring. A broader non-human identity program covers more ground but takes longer to establish.
Both scopes are legitimate. Programs stall when teams choose one without stating it clearly.
Machine Identity Security Best Practices
Securing machine identities starts with an inventory that names an owner. Issuance is only half the problem. Accumulation is what turns forgotten credentials into standing access.
- 1.Discover before you govern. Query certificate authorities, cloud IAM services, secrets platforms, and deployment environments. Reconcile what was issued with what is still running and trusted.
- 2.Attach a human owner. NIST's Security Risks and Recommended Best Practices calls for defined certificate-management roles and responsibilities. An orphaned account and an orphaned certificate fail the same way: nobody is willing to turn them off.
- 3.Automate issuance and renewal together. The CA/Browser Forum TLS Baseline Requirements cap publicly trusted TLS certificates at 200 days from March 15, 2026, falling to 100 days in 2027 and 47 days in 2029. At that point, teams face roughly eight renewals per year for every certificate.
- 4.Test revocation. Removing a credential from an inventory does not prove that every system has stopped trusting it. Rehearse revocation and measure how long it takes to reach each dependent workload.
When rotation is no longer enough
If every renewal requires human intervention, compare the required frequency with the number of renewals the team can execute safely. Where manual renewal still works, tighten the process. Where it does not, move the workload to short-lived credentials issued at runtime.
Automation does not eliminate failure. It replaces a missed calendar renewal with a trust and issuance system that must itself be governed.
How to Secure Machine Identities in Hybrid Cloud
Hybrid environments become fragile where credentials cross boundaries. During a migration, an on-premises batch job and a cloud function may share one database credential because it keeps both paths working. That credential now appears in two inventories, and revoking it may break a workload owned by another team.
Replace shared secrets with federated trust
Federated workload identity removes the shared secret from that seam. Each major provider supports a version of the model:
- AWS IAM Roles Anywhere uses an X.509 certificate from a trusted CA to issue temporary AWS credentials to workloads outside AWS.
- Microsoft Entra workload identity federation lets an external workload exchange a trusted identity-provider token for a Microsoft Entra access token.
- Google Cloud Workload Identity Federation gives on-premises and multi-cloud workloads short-lived access without distributing service-account keys.
Federation does not remove trust. It moves the trust decision from a stored secret into a policy object. That is usually a better object to govern, but it still needs an owner, a review path, and tested revocation.
How to Choose a Machine Identity Management Solution
Most enterprises manage machine identities through tools bought for different reasons. The useful question is which gap the next tool closes.
Discovery coverage
Ask which systems the tool queries directly and which identities it infers. A certificate-authority log shows what that CA issued. Endpoint scanning shows what is deployed on reachable systems, including certificates issued elsewhere. Neither view is complete on its own.
Ownership resolution
A record containing a hostname and serial number is an artifact. A record connected to a system, team, and person who can approve its removal is an inventory. Ask how the tool establishes ownership when the issuing system does not record it.
Automation surface
Automation becomes essential as publicly trusted TLS certificate lifetimes fall toward 47 days. Confirm support for ACME, defined in RFC 8555, across both public and private CAs. Then test renewal failure: a silent retry and a paged alert produce very different Monday mornings.
Cross-type reconciliation
Certificates, keys, tokens, and workload identities live in different systems. Ask whether the product connects them to one workload and owner or simply presents four lists side by side.
A team with one certificate authority and one cloud account may not need a cross-type platform. Certificate automation and secrets management may cover that environment. The calculation changes when credentials issued in one system are trusted in another and nobody can say who owns them. At that point, the gap is inventory rather than issuance, and a certificate tool alone will not close it.
The Future of Machine Identity Security
The direction is already published. Publicly trusted TLS certificate lifetimes fall to 47 days in March 2029, making automation a requirement rather than a preference. Manual renewal at that frequency is a staffing decision most teams will decline to make.
Workloads are outliving their credentials
Or, increasingly, the reverse. Datadog's container research found that almost two-thirds of Kubernetes containers run for less than ten minutes and about a third for less than one. Credentials frequently survive beyond the workload that requested them.
At the same time, identity sprawl grows through automation that creates credentials without adding employees. Credential growth is no longer tied to headcount. The New Identity Manifesto reaches the same conclusion from another direction: identity systems built around employee records extend poorly to actors that are not employees.
Cryptographic agility becomes an inventory problem
NIST released its first three post-quantum cryptography standards in August 2024. FIPS 203, 204, and 205 cover ML-KEM for key establishment and ML-DSA and SLH-DSA for digital signatures.
Moving to new algorithms will require organizations to locate affected certificates, update issuance systems, and reissue credentials over time.
Organizations that can enumerate and replace their certificates automatically will experience that transition as a project. Everyone else will experience it as an archaeology dig.
Governing Machine Identities With NewCore
The problem left by shorter certificate lifetimes is not renewal alone. The estate keeps adding identity types faster than any one system of record can absorb them, while the window to act on each credential keeps shrinking.
Employee-driven identity systems answer questions about people. They were not built to tell you which workload still holds the key a CI pipeline generated in 2022, or who is allowed to turn it off. Discovery has to come before governance because nobody can assign an owner to an identity nobody has enumerated.
- Identity Discovery: connects directories, IdPs, IGA, PAM, cloud, SaaS, infrastructure, and AI systems in one identity graph. It maps identities, accounts, credentials, owners, and access paths that otherwise remain fragmented across separate tools.
- Plain-language search: lets teams ask which machine identities still reach production, which credentials lack owners, and which grants have gone stale without manually cross-referencing consoles.
- Agentic Governance: brings AI agents into the same identity plane with their own owner, authority source, lifecycle, and policy ceiling.
- Machine-Speed Security: evaluates agent access as it happens and supports scoped, time-bound credentials and fast revocation for identities operating beyond human review cycles.
NewCore is not a certificate authority, and it does not replace certificate lifecycle management or a secrets platform. It works alongside those systems and answers the question none can answer alone: which machine identities exist across the estate, how are they connected, and who owns them? The identity discovery and unification layer is where that shared view is built.
A credential with no owner is not managed. It is merely recorded.
The estate already runs on machine identities. Govern them at the speed they are created.
Frequently Asked Questions
Do service accounts count as machine identities?
Usually, although terminology varies. A Kubernetes service account authenticating a pod is clearly a machine identity. A SaaS account used for automation is also a non-human identity, but it may rely on a password or token and follow a less structured lifecycle. Both need an owner, inventory record, and revocation path.
Who should own a machine identity?
Ownership belongs with the team operating the workload. Issuing teams know the credential exists; operating teams know whether the service still runs and can manage rotation or revocation. If no operating team can be identified, treat the identity as a removal candidate and investigate before renewing it automatically.
What should a team do about a certificate whose owner cannot be found?
Start with endpoint logs, connection telemetry, deployment records, and certificate-management data to determine whether the certificate is still in use. If no dependency appears, use a staged revocation or controlled disablement with monitoring and a rollback plan. Active traffic without an owner is a live dependency, not permission to renew indefinitely.
Do the CA/Browser Forum lifetime limits apply to internal certificates?
No. The TLS Baseline Requirements govern publicly trusted certificates that chain to roots distributed through browser and operating-system trust stores. Private CAs set their own validity periods. Some organizations mirror the public schedule internally to avoid maintaining separate renewal models.
Are machine identities and secrets the same thing?
No. A machine identity is the principal representing a workload, device, or service. A secret is credential material, such as a password, API key, or private key, that may authenticate that identity. Machine identities may also use federated trust or workload attestation without storing a long-lived secret. Secrets platforms protect credential material; identity systems establish what that material represents and what it may access.
