03.15.03: for authenticators in the possession of individuals and by 03.01.01

To meet the 03.15.03: for authenticators in the possession of individuals and by 03.01.01 requirement, you must control how user-held authenticators (passwords, tokens, smart cards, MFA devices, private keys) are issued, protected, replaced, and revoked, and align those controls with your broader access control implementation referenced by 03.01.01. Operationalize it by defining “authenticator types,” enforcing secure lifecycle workflows, and retaining assessment-ready evidence. ¹

Key takeaways:

• Scope the authenticators you allow, then standardize issuance, protection, and revocation for each authenticator type.
• Tie authenticator control operation to your access control program so assessors see consistent enforcement under 03.01.01.
• Evidence matters as much as configuration: keep system settings, logs, tickets, and procedures that prove controls operate over time.

03.15.03 sits in the “System and Communications Protection” family in NIST SP 800-171 Rev. 3, but it lands operationally in identity and access management (IAM): you are being asked to manage authenticators that people physically possess or personally control. That includes passwords users know, but the phrasing “in the possession of individuals” commonly shows up in assessments when teams roll out MFA tokens, smart cards, mobile authenticators, FIDO keys, or certificate-based authentication and then fail to manage the lifecycle with the same rigor as accounts.

The second half of the requirement name, “and by 03.01.01,” is your implementation hint: assessors will expect authenticator handling to align with your access control baseline. If your access control rule says only approved users can access CUI systems, then weak authenticator lifecycle (shared tokens, unmanaged lost devices, no revocation, no proof of issuance) undermines that rule. Your goal is a tight, auditable chain: approved identity → issued authenticator → protected use → rapid recovery/revocation → periodic governance. ¹

Regulatory text

Requirement (provided excerpt): “NIST SP 800-171 Rev. 3 requirement 03.15.03 (for authenticators in the possession of individuals and by 03.01.01).” ¹

Operator interpretation of what you must do:

• Define and control authenticators that users possess (physical or user-controlled authenticators) through documented rules and enforced processes.
• Connect authenticator controls to your access control program (the “by 03.01.01” linkage). Your authenticator requirements must support the access decisions you make for CUI systems and accounts. ¹

Because the excerpt is high-level, your implementation needs to be assessment-ready: clear scope, repeatable procedures, technical enforcement where possible, and evidence that the controls operate consistently. ¹

Plain-English interpretation (what it means in practice)

You must manage user authenticators like controlled security assets. For any authenticator that a person holds or controls (passwords, MFA factors, keys, certificates, smart cards, recovery codes), you need rules for:

• Issuance (who can get one, how identity is verified, approvals)
• Protection (how it’s stored, used, and not shared)
• Replacement (lost/damaged, role change, device change)
• Revocation (termination, compromise, inactivity, suspected theft)
• Monitoring and review (detect anomalies and confirm the process works)

If your environment supports CUI, “good intentions” are not enough. Assessors typically look for proof that you can trace an authenticator from request to deprovisioning, and that exceptions are controlled. ¹

Who it applies to

Entities

• Federal contractors and subcontractors handling Controlled Unclassified Information (CUI) in nonfederal systems. ¹
• Any nonfederal organization operating systems that process, store, or transmit CUI under contractual or flow-down requirements. ¹

Operational contexts

• Corporate IAM (SSO, directory services, MFA platform)
• Endpoint/device management (MDM for mobile authenticators, smart card middleware)
• PKI/certificate operations (issuance, renewal, revocation)
• Help desk workflows (password resets, lost token handling)
• HR offboarding and access removal
• Third-party access (managed service providers, consultants) where individuals hold authenticators tied to your environment

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

1) Set scope: list “approved authenticator types”

Create an authenticator inventory standard that answers:

• What authenticators are allowed for CUI systems (password + MFA, FIDO key, smart card, certificate, etc.)?
• Are any authenticators prohibited (shared accounts, shared tokens, emailed one-time codes, local-only passwords without MFA for remote access)?
• Which systems are “in scope” for CUI access? ¹

Deliverable: Authenticator Standards document (or IAM Standard) mapped to your access control policy expectations referenced by 03.01.01. ¹

2) Define lifecycle workflows (issue, replace, revoke)

For each authenticator type, document the workflow with required approvals and verification:

• Issuance: identity proofing steps, request source, manager approval, ticketing requirements, asset assignment
• Replacement: lost/damaged procedure, temporary access rules, identity verification at help desk, invalidate old authenticator
• Revocation: termination trigger, compromise trigger, contractor end date, role change, inactivity handling
• Emergency access: break-glass accounts and their authenticator handling (who can access, how it’s logged, how it’s rotated)

Keep it simple: one page per authenticator type is often enough, but it must be actionable for IT and the service desk. ¹

3) Enforce “possession means personal control”

Operational controls to implement:

• No sharing rule for authenticators (explicitly covers tokens, smart cards, mobile authenticators, recovery codes).
• Unique assignment: each authenticator must map to one individual identity in your IAM system.
• Secure storage: require device-level protections for mobile authenticators (screen lock, encryption) where your organization manages the device; document compensating controls for BYOD. ¹

4) Implement technical controls that backstop the process

Pick the controls that fit your stack:

• Centralize authentication through your IdP/SSO where possible so authenticator policy is consistent.
• Enforce MFA for CUI system access based on conditional access rules (device trust, network, geo where appropriate).
• Require phishing-resistant authenticators for high-risk roles if your risk model supports it, and document the decision either way.
• Disable legacy authentication paths that bypass MFA (common assessment finding). ¹

5) Connect authenticator handling to 03.01.01 operationally

Because the requirement explicitly references 03.01.01, ensure your access control control-set and your authenticator processes match:

• Your user provisioning process must not complete until an approved authenticator is issued and recorded.
• Your access reviews should confirm users still possess approved authenticators (or the account is disabled).
• Offboarding must include authenticator revocation steps, not only account disablement. ¹

6) Build recurring evidence collection (don’t scramble at assessment time)

Set a cadence to collect evidence that proves operation:

• A sample of issuance tickets showing identity verification + assignment
• A sample of revocation actions tied to HR terminations or contract ends
• Logs or reports showing MFA enforcement for in-scope apps
• Exception register entries with approvals and time limits ¹

Daydream (as a workflow, not a buzzword) typically fits here: map 03.15.03 to your policies, assign control owners, schedule recurring evidence pulls, and keep artifacts in one place so you can answer assessor requests quickly without rebuilding the story each time. ¹

Required evidence and artifacts to retain

Maintain artifacts that show both design and operation:

Design artifacts

• Access Control Policy and IAM/Authenticator Standard that lists approved authenticator types and handling rules ¹
• Procedures/playbooks for issuance, replacement, revocation, and emergency access
• Role definitions and who can approve issuance or exceptions

Operational artifacts

• Service desk tickets for issuance/replacement with identity verification notes
• HR offboarding records mapped to account disablement and authenticator revocation actions
• IdP/MFA configuration screenshots or exported settings (conditional access rules, MFA requirements)
• Authentication logs showing MFA challenge and success, plus failed attempts for monitoring
• Certificate issuance and revocation logs if you use PKI
• Exception register with compensating controls and expiry

Common exam/audit questions and hangups

Assessors and internal audit tend to focus on a few friction points:

• “Show me how you ensure authenticators are uniquely assigned to an individual.”
• “What happens when someone loses a token or phone? How fast do you revoke the old factor?”
• “Can any system path bypass centralized MFA?”
• “How do contractors get authenticators, and how do you recover them at end of engagement?”
• “Where is the evidence that this is happening repeatedly, not as a one-time cleanup?” ¹

Frequent implementation mistakes (and how to avoid them)

1. Policy says ‘MFA everywhere,’ but legacy protocols still work.
   Fix: test real login paths (IMAP/SMTP legacy auth, service accounts, local admin) and document exceptions with mitigations. ¹

2. Help desk resets factors without strong identity verification.
   Fix: require documented verification steps and capture them in tickets; restrict who can reset MFA for privileged roles. ¹

3. No linkage between HR offboarding and authenticator revocation.
   Fix: integrate HR termination feed with IAM deprovisioning; include authenticator revocation as a checklist item with evidence. ¹

4. Exceptions become permanent.
   Fix: require time-bound exceptions, business owner approval, and periodic review; expire exceptions by default. ¹

5. You can’t prove possession controls for third parties.
   Fix: contractually require individual accounts and approved authenticators; enforce via your IdP, and revoke promptly at end of work. ¹

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so this page avoids specific enforcement claims.

Practically, weak authenticator lifecycle creates a direct path to unauthorized access to CUI: lost tokens that still work, stale contractor factors, shared authenticators, and “MFA-enabled” environments with bypass routes. The assessment risk is also straightforward: teams often have controls configured but cannot produce clean evidence that issuance and revocation are controlled and repeatable. ¹

Practical 30/60/90-day execution plan

Because this requirement is operational, the fastest path is to standardize authenticators and evidence capture first, then harden edge cases.

First 30 days: Stabilize scope and stop the bleeding

• Identify in-scope CUI systems and their authentication methods. ¹
• Publish an “approved authenticator types” standard and a no-sharing rule.
• Ensure offboarding includes disabling accounts and revoking MFA factors where your platform supports it; document the steps.
• Start an exception register for any system that cannot meet the standard yet.

Days 31–60: Make it repeatable

• Implement documented issuance and replacement workflows via ticketing with required fields (identity verification, approvals, assignment). ¹
• Centralize authentication for key CUI applications under your IdP/SSO where feasible.
• Configure monitoring reports: users without MFA, recent factor resets, dormant accounts with active factors.

Days 61–90: Close bypasses and prove operation

• Test for bypass routes and disable legacy authentication where possible; document remaining exceptions and compensating controls. ¹
• Run an internal mini-assessment: sample tickets, offboarding cases, and logs; confirm you can trace authenticator lifecycle end-to-end.
• Establish recurring evidence collection in a GRC workflow (Daydream or equivalent): scheduled exports, ticket samples, and configuration snapshots stored with control ownership and review notes. ¹

Frequently Asked Questions

Does 03.15.03 only cover physical tokens and smart cards?

Treat it as covering any authenticator an individual controls, including passwords, MFA app factors, FIDO keys, smart cards, certificates, and recovery codes. The operational expectation is lifecycle control and proof of unique assignment. ¹

What does “and by 03.01.01” mean for implementation?

Build your authenticator rules to support your access control baseline: provisioning, access reviews, and offboarding should all reference authenticator status. Assessors will look for consistency between access control decisions and authenticator handling. ¹

How do we handle BYOD mobile authenticators for contractors?

Decide whether BYOD is allowed for CUI access, document the conditions, and enforce them with IdP policy where you can. If you can’t enforce device controls, document compensating controls and keep the approval in your exception register. ¹

What evidence is most convincing in an assessment?

Provide a small, coherent package: the authenticator standard, the procedure, a handful of issuance/revocation tickets, and IdP configuration outputs plus logs that show enforcement. The goal is traceability from policy to operation. ¹

Are shared break-glass accounts automatically noncompliant?

Shared authenticators create assessment risk because they break individual accountability. If you keep break-glass access, tightly control the authenticator, log every use, and rotate credentials after use with documented approvals. ¹

How should we treat service accounts under this requirement?

This requirement name targets authenticators in an individual’s possession, but service accounts often create bypass paths around your access control intent. Document service account authentication separately, restrict where credentials can be used, and prevent service accounts from becoming “shadow user” access. ¹

Footnotes

1. NIST SP 800-171 Rev. 3