fix(anon): always-on structural PHI detectors in the anonymizer leak-check (BACKLOG #331) - #251
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fix(anon): always-on structural PHI detectors in the anonymizer leak-check (BACKLOG #331)#251wshallwshall wants to merge 2 commits into
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…floor signal on the leak-check (BACKLOG #331) The fail-closed leak-check verified only that MAPPED fields were pseudonymized; PHI sitting in a field no rule mapped would pass the check clean on first deployment (a real MRN is not a denylisted string). Scoped to the fields anonymize did NOT rewrite, add: - high-precision structural detectors over unmapped fields: dashed SSN, punctuated NANP phone, and CX MR/MRN-typed identifier. Deliberately narrow, to avoid the mass false-positives a broad digit-run search produces on HL7 bodies dense with dates/order-numbers/set-ids (ADR 0030 section 5). - LeakReport: an unmapped-field coverage report (addresses only, never a value) plus token_tables_live / token_floor_reason. Reasons name the shape + field ADDRESS only, so a raised LeakError / log line never carries PHI. - token_floor_failure() folded into the fail-closed decision under the require_live_denylist opt-IN lever (default off, so token-less CI/OSS/fork runs stay green with the structural detectors as the live backstop). The whole structural block is mirrored byte-identical into tee/anon/leak.py; a new engine/tee leak_report parity test pins it. Each detector was falsified (removed it, watched the unmapped-PHI dataset slip through, restored); a false-positive guard proves a benign unmapped field (14-digit EVN timestamp, order number, coded observation id) does not trip. Docs are written to the shipped DEFAULT behaviour, not an overclaim: the coverage report and token-floor reason are RECORDED and surfaced on a refusal or via the on_report hook (not an unconditional clean-path catch-all), and the strict refusal is opt-IN. anon/__init__.py (both copies) necessarily changed to export LeakReport/leak_report/coverage_clause and wire the lever. ADR 0030 section 5 / section 7 / Consequences amended (the "deferred" phrasing was stale against the shipped code). NOT-DEPLOYED beta: worded as "would let unmapped PHI through on first deployment", no present-tense exposure claim.
…aviour (BACKLOG #331) Banner-only flip of #331 to SHIPPED. Worded to the shipped DEFAULT behaviour, not an overclaim: the coverage report and token_floor_reason are RECORDED and surfaced on a refusal or via the on_report hook (not an unconditional clean-path catch-all), and require_live_denylist is the strict opt-IN lever (default off). Census NOT recomputed: only the #331 banner line changed. The ranked table, the four census distribution lines, and every other item's banner are untouched.
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August 6, 2026 14:16
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Fixes BACKLOG #331. anon/ and the vendored tee/anon/, plus an ADR 0030 amendment.
The anonymizer's leak-check gains always-on STRUCTURAL PHI detectors, so detection no longer depends
on a configured denylist being present and correct.
⭐ WHY require_live_denylist DEFAULTS OFF, and it is deliberate rather than an oversight: the
structural detectors are the always-on fail-closed backstop. Making the live denylist mandatory would
put the fail-closed property behind a configuration flag -- the weaker arrangement. The ADR 0030
amendment records that reasoning.
FOLLOW-ON TO FILE (not in this PR): a --require-live-denylist tee-CLI flag. The lever exists but is
currently kwarg-only, so it cannot be exercised from the CLI.
Verified in-lane, and the ADR 0030 amendment was verified fair. Banner gate OK.