Execute System Security Engineering Processes
Domain 1 asks you to show how security engineering is executed as a life-cycle discipline, not a late review. The exam tests your ability to integrate security objectives into ISO/IEC 15288 technical processes, tailor NIST SP 800-160 practices, and produce evidence that requirements were derived, allocated, verified, and validated. Expect questions on process entry and exit criteria, technical reviews, configuration control, and the SSE-CMM maturity view.
Core rules
- Establish security objectives from mission, threat, and compliance inputs before architecture is baselined.
- Treat security as an architectural property: allocate controls to components and interfaces, not only to documents.
- Maintain bidirectional traceability from stakeholder needs to security requirements, design, test cases, and acceptance evidence.
- Use technical reviews (SRR, PDR, CDR, TRR) as decision gates with explicit security exit criteria.
- Verify the implementation and validate that the delivered system meets stakeholder security needs in its intended environment.
- Apply configuration management so changes are assessed for security impact and re-verified.
Worked example
A ground terminal must protect command uplinks. At SRR, the team derives a confidentiality and integrity requirement from the mission threat model and applicable control baselines. The requirement is allocated to a cryptographic module and an interface boundary; a test case proves the module rejects unauthenticated commands; validation demonstrates the operator can execute the mission under the approved key-management concept. The trace record links need, requirement, design element, test, and result.
Traps
Checklist compliance without threat context; treating verification and validation as synonyms; missing interface and supply-chain requirements; letting the security plan diverge from the systems engineering plan; and claiming risk closure because a control exists.