id: "SC-03(05)" title: "Layered Structures" family: "SC" family_name: "System and Communications Protection" sort_id: "sc-03.05" priority: "P1" implementation_level: "system" parent: "SC-03" enhancement: True


Statement

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.

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.

Assessment Objective

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.

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

System/network administrators

organizational personnel with information security responsibilities

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