SC-50 asks you to implement software enforced separation and policy enforcement mechanisms between the security domains you define. NIST says system owners may want more strength of mechanism for particular threats and environments.
It pairs with SC-49, which is the hardware version. 800-53 binds federal systems and contractors, and is a reference for the rest of us.
What it means in practice
Most companies already do this. Network segmentation, virtual firewalls, container and namespace isolation, and separate cloud accounts are software mechanisms that keep one domain from reaching another. The control asks you to name the domains and prove the rules hold.
Evidence to collect
- A list of domains, for example production, staging, corporate and customer tenants.
- Segmentation rules or security group exports.
- A test showing a blocked connection between domains.
Common gaps
Domains described in a policy but not visible in the network config. Rules that allow any internal traffic.
How to implement it
Start with production and everything else. Add deny by default rules, export them on a schedule, and keep a test result.
Quick check
How is SC-50 different from SC-49?
SC-50 uses software mechanisms. SC-49 uses hardware, which NIST calls stronger.
