AC-4(2) - Information Flow Enforcement | Processing Domains

Use protected processing domains to enforce [Assignment: organization-defined information flow control policies] as a basis for flow control decisions.


ID: AC-4(2)
Enhancement of : AC-4

Space Segment Guidance

Processing domains in space systems create logical or physical boundaries that isolate different classes of data and services, preventing unauthorized cross-domain flows. Within a satellite bus, hosting multiple payloads, for instance, each domain can correspond to a unique security or mission need—such as separating mission command functions, payload data analysis, and external communications handling. Engineers often implement hardware-enforced domains (e.g., memory management units or hypervisor technology) alongside software-based controls to ensure domain isolation persists even under stress conditions such as radiation-induced single-event upsets. When integrated with validated domain-switch mechanisms, these processing domains enable the vehicle to handle diverse operational requirements while protecting critical command channels. The result is a secure execution environment that reduces the risk of unauthorized data exchange, malicious escalation, or unintentional data corruption, enhancing overall mission assurance in contested environments.