3.13.16Encrypt CUI at rest
CUI sitting on disks and in storage is protected.
The requirement, verbatim
NIST SP 800-171 Rev. 2 · 3.13.16Protect the confidentiality of CUI at rest.
NIST's discussion
Information at rest refers to the state of information when it is not in process or in transit and is located on storage devices as specific components of systems. The focus of protection at rest is not on the type of storage device or the frequency of access but rather the state of the information. Organizations can use different mechanisms to achieve confidentiality protections, including the use of cryptographic mechanisms and file share scanning. Organizations may also use other controls including secure off-line storage in lieu of online storage when adequate protection of information at rest cannot otherwise be achieved or continuous monitoring to identify malicious code at rest.
NIST SP 800-171 Rev. 2, discussion under 3.13.16. Whitespace normalised; wording unchanged.
Assessment objectives
An assessor decides each of these separately. The requirement is met only when every objective is.
- [a] the confidentiality of CUI at rest is protected
NIST SP 800-171A, determination statements for 3.13.16.
For assessors: examine, interview, test
NIST SP 800-171A names what an assessor may examine, whom they may interview, and what they may test for this requirement. Assessors select from these lists; they are not a checklist of everything you must produce.
Examine
- System and communications protection policy
- procedures addressing protection of information at rest
- system 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
- System or network administrators
- personnel with information security responsibilities
- system developer
Test
- Mechanisms supporting or implementing confidentiality protections for information at rest
NIST SP 800-171A, potential assessment methods and objects for 3.13.16.
Evidence
No evidence examples are published for this requirement yet. The objectives above are what an assessor checks; evidence is whatever shows each one is true in your environment, dated and kept with your system security plan.
Scoring weight
Worth 1 point. Not meeting this requirement subtracts 1 from your 110-point SPRS score.
DoD NIST SP 800-171 Assessment Methodology v1.2.1 weighting, as carried in the Bedrock scoring table. The score starts at 110 and subtracts the weight of every requirement not met.
In Rev. 3
Rev. 2 is what your contract requires today. A standing DoD class deviation keeps Rev. 2 in force; NIST has published Rev. 3, but it is not adopted for contracts. In Rev. 3 this requirement is withdrawn and incorporated elsewhere: 03.13.08 Transmission and Storage Confidentiality.
See the Rev. 2 and Rev. 3 wording word by word, or start with the status page.
Related requirements
Where this page's facts come from
- Requirement text
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.basicRequirement@rev2
- Discussion
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.discussion@rev2
- Practice name
- bedrock-cmmc-api@89b8e8e:migrations/004_reference_requirements.sql#Requirement.title@rev2 (CMMC Assessment Guide practice name)
- Objectives
- bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2
- Examine, interview, test
- bedrock-cmmc-api@89b8e8e:migrations/005_reference_objectives.sql#AssessmentObjective.description@rev2 ({examineGuidance, interviewGuidance, testGuidance})
- Level
- bedrock-cmmc-api@89b8e8e:migrations/021_fix_level1_requirements.sql#Requirement.cmmcLevel@rev2
- Weight
- bedrock-cmmc-api@89b8e8e:internal/cmmc/requirement_values.go#requirementValues (DoD AM v1.2.1 / eMASS L2 template v3.8)
- Rev. 3 mapping
- bedrock-cmmc-api@89b8e8e:docs/reference/nist-800-171-rev3/normalized/r2_r3_transition_map.json#r2_to_r3
- Plain-language title and summary
- editorial/CMMC Navigator.dc.html#RAW (Foxx Cyber editorial)