Gating Deid Leakage

Gating De-id Leakage in CI

Logs, baselines, and models drift. The only durable defense is a gate that runs on every change and fails closed when de-identification regresses. This skill operationalizes OpenMed's leakage-first ethos into a CI check: recall must stay above the floor and critical leakage must be exactly zero, or the build goes red.

When to use this skill

• You want a pytest test or CLI step that exits nonzero on de-id regression.
• You need to block PRs that drop PHI recall or introduce a leak.
• You want OpenMed's release gates (ReleaseGate, G1a–G8) enforced in CI.
• You maintain a synthetic held-out PHI set and want it checked automatically.

For the full gate semantics see evaluating-with-leakage-gates; this skill is about wiring it into CI so it fails the build.

Quick start — a pytest gate

# tests/eval/test_deid_leakage_gate.py
import pytest
from openmed.eval import run_suite, ReleaseGate, RELEASABLE

RECALL_FLOOR = 0.99          # direct-identifier recall floor
HELD_OUT = "eval/heldout/phi_synthetic.json"   # SYNTHETIC, committed

@pytest.fixture(scope="module")
def gate_report():
    report = run_suite(
        HELD_OUT,
        suite="golden",
        model_name="OpenMed/Privacy-PII-Detection",
        device="cpu",
        metadata={"family": "PII", "tier": "base", "policy": "hipaa_safe_harbor"},
    )
    return ReleaseGate(milestone="v1.6", policy="hipaa_safe_harbor").evaluate(report)

def test_no_critical_leakage(gate_report):
    # Hard zero: one leaked SSN/credit-card is a breach, full stop.
    assert gate_report.critical_leakage_count == 0, "critical PHI leaked"

def test_recall_floor(gate_report):
    low = {
        label: r
        for label, r in gate_report.per_label_recall.items()
        if r < RECALL_FLOOR
    }
    assert not low, f"recall below floor: {low}"

def test_releasable(gate_report):
    # The structural decision: any failed gate -> QUARANTINED -> red build.
    failed = [c.gate for c in gate_report.gate_results if not c.passed]
    assert gate_report.decision == RELEASABLE, f"quarantined; failed gates: {failed}"

pytest exits nonzero on any failure, so CI turns red automatically.

Quick start — a CLI gate

The harness ships a main() that fails closed (exit 1 on quarantine):

# Produce a candidate report, then gate it. Nonzero exit blocks the job.
python -m openmed.eval.release_gates \
  --candidate eval/out/candidate_report.json \
  --baseline-store eval/baselines/last_green.json \
  --milestone v1.6 --policy hipaa_safe_harbor \
  --output release-gate-report.json

Exit codes: 0 RELEASABLE, 1 QUARANTINED, 2 evaluation error before a report. CI should treat 1 and 2 as failures.

Wire it into GitHub Actions

# .github/workflows/deid-gate.yml
name: de-id leakage gate
on: [pull_request]
jobs:
  gate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: astral-sh/setup-uv@v5
      - run: uv pip install --system -e ".[hf]"
      - name: Run de-id leakage gate
        run: uv run pytest tests/eval/test_deid_leakage_gate.py -q
      # The job fails (red) automatically if pytest exits nonzero.

Workflow

1. Curate a synthetic held-out PHI set and commit it (offsets + labels, no real patient text). Use building-gold-corpus. It must be disjoint from any calibration/training data.
2. Pick the floor from policy. Don't hardcode a magic number you invented — align to the gate's published floors (G1A_V16_RECALL_FLOOR etc. in openmed.eval.release_gates) and the active policy profile.
3. Run the suite → gate the report (pytest fixture above).
4. Assert two invariants: critical_leakage_count == 0 and per-label recall ≥ floor. Optionally assert decision == RELEASABLE for the full G1a–G8 check.
5. Make it required. Mark the job a required status check so a red gate blocks merge — a passing-but-not-required gate protects nothing.
6. On failure, the harness CLI can open/refresh a tracking issue (--issue-on-failure) so the regression is visible, not silently retried.

Hand-off to / from OpenMed

• From evaluating-with-leakage-gates: this skill is the CI wrapper around the same ReleaseGate.evaluate(...) call — reuse its gate semantics.
• From building-gold-corpus: supplies the synthetic held-out fixtures the gate runs against.
• To authoring-model-cards: a green gate's GateReport is the evidence the model card cites under "evaluation".
• Pairs with enforcing-nophi-logging: the gate proves the model doesn't leak; the logging guard proves your runtime doesn't leak.

Edge cases & gotchas

• Fail closed, never open. If the candidate report is missing or the eval errors, treat it as a failure. Don't || true the step.
• A passing F1 is not a passing gate. Recall floor + zero critical leakage are the load-bearing assertions; assert them explicitly even if you also check decision.
• Held-out must stay held-out. If the gate set leaks into calibration or training, the gate measures memorization, not generalization. Keep splits disjoint (see building-gold-corpus).
• Pin the model and milestone. Floors change per milestone (v1.6 vs v2.0); pin both so a "passing" gate doesn't silently weaken.
• No real PHI in CI artifacts or logs. The gate report is offsets/hashes only; don't print fixture text in CI output.
• Baselines are inputs, not outputs of the gate. Promote last-green baselines in a separate, reviewed step — never auto-write them from the gate job.

Standards & references

• HIPAA Safe Harbor de-identification standard (45 CFR 164.514): https://www.hhs.gov/hipaa/for-professionals/privacy/special-topics/de-identification/
• NIST SP 800-188, De-Identification of Personal Information: https://csrc.nist.gov/pubs/sp/800/188/final
• GitHub Actions required status checks: https://docs.github.com/actions/using-workflows/required-status-checks
• OpenMed eval source of truth: openmed/eval/release_gates.py (main, ReleaseGate), openmed/eval/harness.py.