# NIST800 171 3.5.1 — User Identification and Authentication

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_nist800171_351_1a927955b2-nist800-171-351-user-identification-and-authentication
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [NIST SP 800-171 Readiness](https://support.icompaas.com/support/solutions/c_gen_nist800171) › [Identification and Authentication](https://support.icompaas.com/support/solutions/folders/f_gen_cgennist800171_identificationandauthentication)
- Last updated: 2026-05-30
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

NIST800 171 · Control 3.5.1 · Priority: critical · Component: Identification and Authentication

### What this control covers

This control requires the unique identification and authentication of system users, associating each user with processes acting on their behalf. Additionally, users must be re-authenticated under organization-defined circumstances, such as when roles, credentials, or privileged functions change, or after a defined time period. This control supports the Authentication Management capability within the Identification and Authentication (3.5) family.

### Why it matters

Risk is the language an executive team understands; this control connects technical reality to board-level decisions and budget allocation.

### How to implement

#### AWS

Codify the policy intent as **SCPs, AWS Config conformance packs, and Security Hub standards** so the cloud enforces what the document says.

#### Azure

Codify in **Azure Policy initiatives** (built-in regulatory compliance for CIS, ISO 27001, SOC 2, HIPAA) and assign at management-group level.

#### GCP

Use **Cloud Identity** (or Workspace) as the IdP and **IAM** for resource access. Grant roles at the lowest scope (project > folder > org) using **Workload Identity Federation** for CI/CD and **service accounts** for workloads — never download service-account keys when avoidable. Enable **Policy Intelligence** recommenders to right-size privileges and detect dormant identities.

#### Google Workspace

Enforce **2-Step Verification** (preferably hardware keys for admins) for the entire org, set session length to ≤ 12 hours, and disable less-secure-app access. Use **Context-Aware Access** levels to restrict admin sign-in by IP/device posture. Provision and de-provision users via **SCIM** from your HRIS so leavers lose access on day one.

#### GitHub

Require **SSO + SCIM** from your IdP on the organisation; enforce **2FA** org-wide and use **fine-grained PATs** (or, better, GitHub Apps) instead of classic tokens. Restrict **outside collaborators**, require signed commits on protected branches, and use **OIDC** from Actions to short-lived AWS/GCP/Azure credentials rather than stored secrets.

#### Zoho Mail

Make **two-factor authentication** mandatory for all users (TOTP, OneAuth, or YubiKey) in _Admin Console → Security_. Configure **SAML SSO** against your IdP and disable password-based logins for admins. Use **role-based privileges** (Admin / Spam Moderator / Mail Account Admin) and review the _Login history_ report monthly for anomalies.

#### On-premises

Maintain a policy library with a documented review cadence (annual minimum); store in your GRC tool with attestation tracking. Map each policy to controls so an audit pull cites the exact policy clause.

### Evidence to collect

-   `identity_scan` — See the iCompaas Evidence library for the canonical source for this evidence type.
-   `policy_document` — A signed, version-controlled policy stating leadership intent and the named owner.
-   `infra_scan` — See the iCompaas Evidence library for the canonical source for this evidence type.

Identity analytics (Okta, SailPoint, Access Analyzer) demonstrates least-privilege. Signed policy or standard documents the safeguard. Focus: User Identification and Authentication.

### Quick checklist

-   Access — Management / Time
-   Time — Management / Time
-   System — Management / Time
-   Authentication — Management / Time
-   Risk — Management / Time

### Related articles on this site

-   [NIST 800-171 3.1.1 Limit information system access to authorized users, processes acting on behalf of authorized users, or devices (including other information systems).](https://support.icompaas.com/support/solutions/articles/62000229223-nist-800-171-3-1-1-limit-information-system-access-to-authorized-users-processes-acting-on-behalf-of)
-   [CMMC 2.0 AC.1.001 Limit information system access to authorized users, processes acting on behalf of authorized users, or devices (including other information systems)](https://support.icompaas.com/support/solutions/articles/62000229379-cmmc-2-0-ac-1-001-limit-information-system-access-to-authorized-users-processes-acting-on-behalf-of-)
-   [Ensure Access Review is Set Up for External Users in Azure AD Privileged Identity Management (PIM](https://support.icompaas.com/support/solutions/articles/62000229788-ensure-access-review-is-set-up-for-external-users-in-azure-ad-privileged-identity-management-pim)
-   [NIST 800-171 3.5.1 Identify system users, processes acting on behalf of users, and devices.](https://support.icompaas.com/support/solutions/articles/62000229289-nist-800-171-3-5-1-identify-system-users-processes-acting-on-behalf-of-users-and-devices-)

## Related compliance guidance

- [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): The CUI requirements CMMC Level 2 assesses, the SPRS score, POA&M rules and the phased DFARS rollout.
- [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): The federal catalogue 800-171 is derived from — useful when a contract also cites a FedRAMP baseline.