Security requirement
- a.Receive authorization from organizational personnel or roles to assign an individual, group, role, service, or device identifier.
- b.Select and assign an identifier that identifies an individual, group, role, service, or device.
- c.Prevent the reuse of identifiers for [Organization-defined: time period].
- d.Manage individual identifiers by uniquely identifying each individual as [Organization-defined: characteristic].
Discussion
Identifiers are provided for users, processes acting on behalf of users, and devices. Prohibiting the reuse of identifiers prevents the assignment of previously used individual, group, role, service, or device identifiers to different individuals, groups, roles, services, or devices. Characteristics that identify the status of individuals include contractors, foreign nationals, and non-organizational users. Identifying the status of individuals by these characteristics provides information about the people with whom organizational personnel are communicating. For example, it is useful for an employee to know that one of the individuals on an email message is a contractor.
Tailoring decisions required
Resolve these values through the governing organization’s approved tailoring and risk-management process before declaring the requirement implemented.
Implementation perspective
Treat Identifier Management as a CUI protection outcome that must be reflected in the system boundary, documented implementation, operational behavior, and assessment evidence. Pay particular attention to identity proofing, authentication strength, authenticator lifecycle, and resistance to credential compromise.
- Confirm the requirement is in scope for the CUI system components, services, users, and external connections being assessed.
- Resolve every organization-defined parameter through an approved governance and tailoring process.
- Map each clause of the requirement to an accountable owner, implementation mechanism, and evidence source.
- Verify that inherited and shared implementations are supported by current provider evidence and responsibility boundaries.
- Collect evidence during normal operation and review changes, exceptions, and deficiencies on a risk-based cadence.
Questions to ask
- Which CUI assets, data flows, users, and services are protected by this requirement?
- Which portions are implemented locally, inherited, shared, or not applicable, and what evidence supports that determination?
- Do the system security plan, deployed configuration, operating process, and assessment evidence tell the same story?
- What change, incident, or threshold should trigger reassessment?
Evidence and validation
- identity proofing records
- authenticator issuance and revocation logs
- MFA and federation configuration
- credential inventories and rotation evidence
Common failure patterns
- MFA applied only to interactive users
- service credentials without ownership or rotation
- weak recovery paths that bypass strong authentication
- federated trust not reviewed after partner changes
Assessment objectives and methods
Assessment objectives (5)
- a.
authorization is received from organizational personnel or roles to assign an individual, group, role, service, or device identifier.
- b.
an identifier that identifies an individual, group, role, service, or device is selected.
- b.
an identifier that identifies an individual, group, role, service, or device is assigned.
- c.
the reuse of identifiers for [Organization-defined: time period] is prevented.
- d.
individual identifiers are managed by uniquely identifying each individual as [Organization-defined: characteristic].
Examine
- identification and authentication policy and procedures
- procedures for identifier management
- procedures for account management
- system design documentation
- list of system accounts
- list of characteristics identifying individual status
- system configuration settings
- list of identifiers generated from physical access control devices
- system security plan
- other relevant documents or records
Interview
- personnel with identifier management responsibilities
- personnel with information security responsibilities
- system developers
- system administrators
Test
- mechanisms for supporting or implementing identifier management
Source NIST SP 800-53 controls
These controls are referenced by the official SP 800-171 Rev. 3 OSCAL record. Open the corresponding control pages for complete control text, enhancements, D3FEND mappings, and related learning.
Authoritative sources
- NIST SP 800-171 Revision 3 official publication ↗
- NIST SP 800-171A Revision 3 official publication ↗
- NIST OSCAL Content release used for this import ↗
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. The official publications, the responsible federal agency, and the governing contract or agreement determine applicability, tailoring, assessment depth, and required implementation.