Sprint 18 Engineering Log

Program Context

• Phase: Phase 5.5
• Sprint: Sprint 18
• Status: Completed
• Primary Architecture Layers: Control Plane, Runner Plane, C2 Adapter Plane, Key and Secret Plane

Architectural Intent

Produce a formal threat model baseline for control plane integrity and zero-trust hardening priorities.

Implementation Detail

Completed Sprint 18 deliverables:

• Full STRIDE threat model across Control, Runner, C2, and Vault/HSM planes.
• Explicit trust boundary diagram linking Operator, Control Plane, OPA, Vault, Broker, Runner, C2, and Ledger.
• Enumerated malicious operator, compromised runner, supply-chain compromise, and cross-tenant escalation scenarios.
• Mapped threat scenarios to existing mitigations in orchestrator, runner, policy, armory, and security scripts.
• Captured unresolved risks in a formal backlog mapped to planned sprints (19, 20, 21).
• Added per-task PR templates under docs/dev-logs/sprint-18/pr-templates/.

Security and Control Posture

• Control plane risk posture is now formally documented with STRIDE traceability.
• Threat-to-mitigation mapping is now explicit and test-validated in QA automation.
• Remaining high-risk controls are queued for implementation in Sprint 19-21 tasks.

QA and Validation Evidence

Command:

• PYTHONPATH=src .venv/bin/pytest -q tests/qa/test_sprint18_threat_model_qa.py

Result:

• 3 passed

Risk Register

Residual risks are captured in:

• docs/RISK_BACKLOG.md

Forward Linkage

Sprint 19 starts control plane integrity hardening (signed config, policy hash pinning, and tamper-evident controls).