SIP-018 — Information-Flow Segmentation

Go to Annex C: Requirements

The information-flow Model SHALL define mechanisms for enforcing segmentation based on applicable Governance or security constraints.

Not all structured information may flow among all architectural elements, Domains, Jurisdictions, or security environments. Governance and security constraints may restrict which information can move, where it can move, who may receive it, and which processing may be applied.

Explicit segmentation mechanisms allow the Reference Architecture to constrain information flows according to applicable Policies and authorities. They also make the placement and effect of enforcement visible for review, verification, and Traceability.

The Submission satisfies this requirement when the information-flow Model:

1. Represents information-flow segments and the boundaries between them
2. Associates each segment with its applicable Governance and security constraints
3. Defines architectural points at which segmentation constraints are evaluated or enforced
4. Supports restriction of a flow according to its source, destination, content, context, or applicable Policy
5. Represents whether a flow is permitted, rejected, filtered, redirected, or transformed
6. Prevents information from bypassing the applicable segmentation mechanisms
7. Preserves Traceability to the constraint and Authority governing an enforcement decision
8. Supports recording of rejected or modified flows when required by the applicable Policy
9. Defines segmentation independently of a required implementation technology

Segmentation may reflect Governance boundaries, organizational boundaries, Jurisdictional boundaries, security classifications, trust zones, compartments, information-handling restrictions, or other applicable constraints.

The Reference Architecture defines the mechanisms and relationships required for enforcement. Individual realizations select the technologies used to implement them.