SC.L2-3.13.16 · Level 2

Protect the confidentiality of CUI at rest.

NIST SP 800-171 Rev 2 · §3.13.16

Assessment objectives

From NIST SP 800-171A · 1 objective must be met to satisfy this control

3.13.16[a] Protect the confidentiality of CUI at rest.

Examine

[SELECT FROM: System and communications protection policy; procedures addressing protection of information at rest; security plan; system design documentation; list of information at rest requiring confidentiality protections; system configuration settings and associated documentation; cryptographic mechanisms and associated configuration documentation; other relevant documents or records].

Interview

[SELECT FROM: System or network administrators; personnel with information security responsibilities; system developer].

Test

[SELECT FROM: Mechanisms supporting or implementing confidentiality protections for information at rest].

What we look for in practice

The following are placeholder notes that should be refined based on practice experience.

What assessors look for in practice. Documented evidence that this control is implemented across all CUI-handling systems within scope. Specific artifacts vary, but expect requests for written procedures, system configurations, and operational records demonstrating the control is active.

Common failure patterns. Typical issues include incomplete documentation, inconsistent implementation across systems, and missing periodic review records. Refine this section as your practice accumulates direct assessment experience.

Strong evidence looks like. Formal policy referencing this control, technical configurations demonstrating enforcement, periodic review logs with sign-off, and procedures for handling exceptions.

Scoring and POA&M context. 1-point control under the DoD Assessment Methodology. Lower scoring impact, but still required for full compliance. POA&M-eligible — deferral up to 180 days is allowed under conditional certification per 32 CFR 170.21.