Layered Structures
LOW MODERATE HIGHRequirements NIST SOURCE
Implement security functions as a layered structure minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers.
Discussion (NIST Supplemental Guidance)
The implementation of layered structures with minimized interactions among security functions and non-looping layers (i.e., lower-layer functions do not depend on higher-layer functions) enables the isolation of security functions and the management of complexity.
Implementation Guidance
Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.
No engineering interpretation has been authored for SC-3(5) yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.
Assessment
Assessment Objectives
- security functions are implemented as a layered structure, minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers.
Examine
[SELECT FROM: System and communications protection policy; procedures addressing security function isolation; system design documentation; system configuration settings and associated documentation; system audit records; system security plan; other relevant documents or records].
Interview
[SELECT FROM: System/network administrators; organizational personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for implementing security functions as a layered structure that minimizes interactions between layers and avoids dependence by lower layers on functionality/correctness of higher layers; mechanisms supporting and/or implementing security functions as a layered structure].
Overlays
STIGs & CCIs
No STIG checks or CCI mappings are currently loaded for SC-3(5). This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.
Learn more about STIG/CCI integration →Evidence
Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.
Policy
- System and communications protection policy
- system security plan
Configuration
- system design documentation
- system configuration settings and associated documentation
Testing
- Organizational processes for implementing security functions as a layered structure that minimizes interactions between layers and avoids dependence by lower layers on functionality/correctness of higher layers
- mechanisms supporting and/or implementing security functions as a layered structure
Other Records
- procedures addressing security function isolation
- system audit records
- other relevant documents or records