A Minimal Internal Firewall for Early Breach Arrest

This private technical note describes a phase-governed internal firewall architecture designed to arrest early-stage system breaches through containment rather than classification. The system observes only high-level structural signals and enforces progressively restrictive operational phases, culminating in a hard freeze when integrity rupture is declared. No payload inspection, thresholds, or implementation details are disclosed. This record is shared for timestamping and defensive research purposes.