Minimized Sharing
LOW MODERATE HIGHRequirements NIST SOURCE
Implement the security design principle of minimized sharing in [systems or system components].
Discussion (NIST Supplemental Guidance)
The principle of minimized sharing states that no computer resource is shared between system components (e.g., subjects, processes, functions) unless it is absolutely necessary to do so. Minimized sharing helps to simplify system design and implementation. In order to protect user-domain resources from arbitrary active entities, no resource is shared unless that sharing has been explicitly requested and granted. The need for resource sharing can be motivated by the design principle of least common mechanism in the case of internal entities or driven by stakeholder requirements. However, internal sharing is carefully designed to avoid performance and covert storage and timing channel problems. Sharing via common mechanism can increase the susceptibility of data and information to unauthorized access, disclosure, use, or modification and can adversely affect the inherent capability provided by the system. To minimize sharing induced by common mechanisms, such mechanisms can be designed to be reentrant or virtualized to preserve separation. Moreover, the use of global data to share information is carefully scrutinized. The lack of encapsulation may obfuscate relationships among the sharing entities.
Implementation Guidance
Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.
No engineering interpretation has been authored for SA-8(6) 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
- systems or system components that implement the security design principle of minimized sharing are defined;
- <SA-08(06)_ODP systems or system components> implement the security design principle of minimized sharing.
Examine
[SELECT FROM: System and services acquisition policy; procedures addressing the security design principle of minimized sharing used in the specification, design, development, implementation, and modification of the system; system design documentation; security and privacy requirements and specifications for the system; system security and privacy architecture; system security plan; other relevant documents or records].
Interview
[SELECT FROM: Organizational personnel with the responsibility for determining system security and privacy requirements; organizational personnel with system specification, design, development, implementation, and modification responsibilities; system developers; organizational personnel with information security responsibilities].
Test
[SELECT FROM: Organizational processes for applying the security design principle of minimized sharing in system specification, design, development, implementation, and modification; mechanisms supporting the application of the security design principle of minimized sharing in system specification, design, development, implementation, and modification].
Overlays
STIGs & CCIs
No STIG checks or CCI mappings are currently loaded for SA-8(6). 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 services acquisition policy
- system security plan
Configuration
- system design documentation
- system security and privacy architecture
Testing
- Organizational processes for applying the security design principle of minimized sharing in system specification, design, development, implementation, and modification
- mechanisms supporting the application of the security design principle of minimized sharing in system specification, design, development, implementation, and modification
Other Records
- procedures addressing the security design principle of minimized sharing used in the specification, design, development, implementation, and modification of the system
- security and privacy requirements and specifications for the system
- other relevant documents or records