IA-9: Service Identification and Authentication

IA-9: Service Identification and Authentication requires you to uniquely identify and authenticate each service (not just users) before it communicates with devices, users, or other services. Operationalize it by maintaining an authoritative service inventory, issuing strong service identities (certs/keys), enforcing authenticated service-to-service connections by default, and retaining evidence that controls are implemented and monitored. ¹

Key takeaways:

• Treat “services” as first-class identities with ownership, lifecycle controls, and monitoring.
• Block unauthenticated service communications by policy and by technical enforcement (mTLS, signed tokens, managed secrets).
• Evidence matters: inventory, configs, logs, and periodic reviews must be easy to produce on demand.

IA-9 trips up mature programs because it is easy to overfocus on workforce IAM and forget the identities that actually run your environment: workloads, APIs, batch jobs, message queues, databases, and third-party integrations. The control is simple on paper: uniquely identify and authenticate services before they communicate. In practice, you need three things an assessor will recognize immediately: (1) a clear scope of what counts as a “service” in your environment, (2) a standard pattern for how services authenticate (and a default-deny posture for everything else), and (3) repeatable evidence that the pattern is implemented, monitored, and governed.

This page is written for a Compliance Officer, CCO, or GRC lead who needs requirement-level guidance for the ia-9: service identification and authentication requirement. You’ll find concrete implementation steps, the artifacts to retain, common audit questions, and a phased execution plan you can hand to engineering with minimal translation. The goal is assessment-ready operations, not theory. ²

Regulatory text

Requirement (excerpt): “Uniquely identify and authenticate {{ insert: param, ia-09_odp }} before establishing communications with devices, users, or other services or applications.” ¹

Operator interpretation (what you must do)

• “Uniquely identify” means each service has its own identity that is not shared across other services or environments. Shared “one key for all microservices” patterns fail this expectation.
• “Authenticate … before establishing communications” means authentication is part of the connection setup, not an optional application-layer check after a connection is already accepted.
• “Services, applications” includes internally developed components, commercial platforms you operate, and integrations that run with service credentials (including those used to access third-party systems). ¹

Plain-English requirement

Every non-human actor that communicates in your environment must prove who it is before it can talk to anything else. You do this by issuing each service a distinct identity (certificate, key pair, workload identity, or signed token) and enforcing that identity check at the boundary where the connection is established (API gateway, service mesh, message broker, database listener, or mutual TLS endpoint). ¹

Who it applies to (entity and operational context)

Entity scope

• Federal information systems and contractors handling federal data commonly inherit IA-9 expectations through NIST-based requirements. ¹

Operational scope (what to include)

• East-west traffic between microservices.
• North-south API traffic through gateways and reverse proxies.
• Service access to data stores (databases, object storage, secrets managers).
• Async systems (queues, pub/sub, event buses) where publishers and consumers need identity.
• Automation identities (CI/CD runners, infrastructure-as-code pipelines, scheduled jobs).
• Third-party connections where your service authenticates to them, or they authenticate to you.

What you actually need to do (step-by-step)

1) Define “service” for your environment and freeze scope

Create a short scoping statement engineering can follow:

• A “service” is any non-human process with network access that calls or accepts calls (API, RPC, database connection, queue publish/consume, webhook, or admin API).
• Exclusions must be explicit (for example, purely local processes with no network communications). Deliverable: IA-9 Service Scope Statement mapped to where enforcement happens (gateway, mesh, broker, DB). ¹

2) Build an authoritative service inventory (minimum viable)

You need an inventory that supports audit questions like “which services exist, who owns them, and what identity do they use?” Minimum fields:

• Service name (unique), environment (prod/non-prod), owner, data classification handled, communication paths (inbound/outbound), authentication mechanism, credential/cert location, rotation method, last rotation date, monitoring/log source. Practical tip: start with production services only, then expand. Assessors usually care most about production and sensitive data flows.

3) Standardize service identity types and ban shared credentials

Pick approved patterns and document them:

• mTLS with per-service certificates for service-to-service traffic (common for internal east-west).
• Signed tokens (OIDC/JWT) issued to workloads for API calls where token-based auth is standard.
• Broker-native identities for queues (SASL, IAM-based auth, or equivalent) with per-service principals. Policy requirement: “No shared service accounts or shared API keys across services or environments.” If you allow exceptions, require compensating controls and expiry.

4) Enforce authentication “before establishing communications”

This is where IA-9 is won or lost. Your documentation should tie each communication path to an enforcement point:

• API gateway/reverse proxy: require client authentication (mTLS or token) before routing.
• Service mesh: enforce mTLS and authorize identities at the sidecar or policy layer.
• Databases: enforce per-service DB principals; disable anonymous or shared logins.
• Message brokers: require authenticated publish/consume with per-service identities. Deliverable: Service Auth Enforcement Matrix (system boundary → protocol → auth method → enforcement control → logging).

5) Implement lifecycle controls: issuance, storage, rotation, revocation

Assessors look for lifecycle governance as proof the control is operational:

• Issuance: documented process for creating a new service identity (who approves, how it’s named, where it’s registered).
• Storage: secrets must be stored in a managed secret store or equivalent controlled mechanism; prohibit plaintext in repos and build logs.
• Rotation: define how rotation occurs (automated where possible) and how you verify it happened (tickets, logs, certificate expiry monitoring).
• Revocation/decommissioning: tie service offboarding to identity disablement and credential revocation. Keep it practical: a short runbook plus evidence that teams follow it.

6) Monitor and log service authentication outcomes

You need evidence that authentication is enforced and detectable:

• Log successful and failed authentications at the enforcement point (gateway/mesh/broker/DB).
• Alert on patterns that indicate misconfiguration or abuse (sudden spikes in failures, deprecated auth schemes, unknown service identities).
• Review logs during incidents and as part of periodic control checks. Deliverable: Central log queries/dashboards that show service authentication events and policy denials.

7) Assign ownership and create recurring evidence

NIST controls fail in audits when nobody owns them. Assign:

• Control owner (security/GRC accountable)
• Technical owner(s) (platform/IAM/SRE)
• App owner responsibilities (service registration, identity usage) Then define recurring evidence that’s easy to produce. Daydream is often the cleanest way to map IA-9 to a control owner, a procedure, and recurring artifacts so evidence stays consistent across teams and audits. ¹

Required evidence and artifacts to retain

Keep artifacts in a single audit package (or control record) so you can answer quickly:

Core governance

• IA-9 policy or standard for service identities (approved auth patterns, shared-credential prohibition, exception process).
• Service scope statement and boundary diagram.

Inventory and mappings

• Service inventory export (current snapshot) with owners and auth mechanisms.
• Service Auth Enforcement Matrix.

Technical evidence (samples are fine if population is large)

• Configuration screenshots/exports from gateway/mesh/broker/DB showing auth required.
• Certificate/identity issuance records from your identity platform (or CA logs).
• Secrets manager access policies for service credentials.
• Log samples showing service authentication successes/failures and enforcement denials.

Operational proof

• Rotation evidence (automated job output, tickets, change records).
• Deprovisioning evidence (identity revoked when service retired).
• Exceptions register with approvals and expiry dates.

Common exam/audit questions and hangups

Expect these, and prepare one-click evidence:

1. “Show me your service inventory and how you know it’s complete.”
   Hangup: teams confuse CMDB completeness with workload identity coverage. Answer with your inventory source-of-truth and reconciliation method (cloud asset inventory + mesh/gateway registrations).

2. “Do services share credentials?”
   Hangup: legacy systems using a single API key across multiple jobs. Prepare an exception list and a migration plan.

3. “Where is authentication enforced?”
   Hangup: “the app checks a header” is weak if the network accepts unauthenticated connections. Point to gateway/mesh/broker config that blocks unauthenticated sessions.

4. “How do you rotate and revoke service credentials?”
   Hangup: rotation exists “in theory” but no proof. Keep rotation logs, cert expiry monitoring, and change records.

Frequent implementation mistakes (and how to avoid them)

• Mistake: Treating IA-9 as a user IAM control.
  Fix: add “non-human identities” to your IAM program charter and evidence plan.

• Mistake: One service account per team or per cluster.
  Fix: enforce per-service principals; bake identity creation into scaffolding templates.

• Mistake: Authentication without authorization.
  IA-9 is authentication-focused, but auditors often ask “what can this service do?” Pair IA-9 work with clear authorization boundaries (least privilege), even if that maps to other NIST controls.

• Mistake: No documented exception path.
  Fix: create an exceptions register with owner sign-off and expiration. Otherwise exceptions become permanent.

• Mistake: No monitoring of auth failures.
  Fix: define baseline alerts and keep examples of investigations or tuning.

Enforcement context and risk implications

No public enforcement cases were provided in the available source materials for this requirement, so this page focuses on audit and assessment expectations rather than case law.

Risk-wise, weak service authentication commonly translates into:

• Lateral movement risk when internal services accept unauthenticated calls.
• Credential replay risk where long-lived shared keys exist.
• Third-party integration risk when service credentials are poorly governed (loss of a key becomes loss of access control across environments).

In assessments aligned to NIST SP 800-53, the most frequent failure mode is not the absence of a technology, but missing evidence that the control is consistently implemented and governed. ¹

Practical 30/60/90-day execution plan

First 30 days (stabilize and scope)

• Name control owner and technical owners; document responsibilities.
• Publish service definition and minimum inventory fields.
• Inventory production services and the top communication paths (gateway, mesh, broker, DB).
• Choose approved auth patterns (mTLS, workload tokens, broker auth) and document them.
• Create an exceptions register and require expiry for any shared credentials.

Days 31–60 (enforce defaults on priority paths)

• Enforce authenticated connections at one or two central choke points (API gateway and service mesh, or gateway and broker).
• Migrate high-risk services first (sensitive data, internet-exposed, privileged integrations).
• Stand up logging queries and dashboards for service auth outcomes at enforcement points.
• Implement credential issuance and rotation runbooks, with owners and evidence capture.

Days 61–90 (make it repeatable and assessment-ready)

• Expand enforcement to remaining paths (databases, internal admin APIs, remaining brokers).
• Automate service identity issuance in CI/CD scaffolding.
• Run an internal mini-assessment: sample services, prove identity uniqueness, show configs, show logs, show rotation and deprovisioning.
• Package artifacts into a single IA-9 evidence set in your GRC system; Daydream can keep the owner, procedure, and recurring evidence aligned so future audits are a refresh, not a scramble. ¹

Frequently Asked Questions

Does IA-9 require mutual TLS for every service?

IA-9 requires unique identification and authentication before communication, but it does not mandate a single technology in the provided text. mTLS is a common way to meet the requirement for east-west traffic; token-based workload identity can also fit if enforced at connection establishment. ¹

Are shared API keys automatically noncompliant?

Shared credentials undermine “uniquely identify” because multiple services appear as the same caller. If you have legacy shared keys, treat them as time-bound exceptions with compensating controls and a migration plan. ¹

What counts as a “service” for IA-9 in a cloud environment?

Any non-human workload that initiates or accepts network communications should be treated as a service identity, including serverless functions, containers, CI/CD runners, and scheduled jobs. Write down your definition and apply it consistently. ¹

How do we prove “before establishing communications” to an auditor?

Show configurations where the gateway/mesh/broker/DB rejects unauthenticated connections, plus logs of rejected attempts. App-layer checks alone are harder to defend if the network path still allows unauthenticated sessions. ¹

We outsource a component to a third party. Does IA-9 apply?

If the third party operates services that connect to your environment or your services connect to theirs, you still need strong service authentication at the boundary you control. Capture the integration design, the auth method, and monitoring/logging as part of your third-party due diligence package. ¹

What is the minimum evidence set for a first audit pass?

Provide a service inventory snapshot, your service authentication standard, configs proving enforcement at key boundaries, and logs demonstrating authentication outcomes. Add rotation and deprovisioning evidence for a small representative sample of services. ¹

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5