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soft-hash analysis §9.1: pin #000034 Phase 1a landing (mirror of §9.2)

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#000034 Phase 1a landed 2026-05-10 (synthetic-ablation
infrastructure for the Hessian-alignment probe under φ_linear):
bench/scripts/phi_alignment_probe.py + 14 tests + KAT fixture
at bench/fixtures/phi-alignment/synthetic-checkpoints.jsonl.

Same closure-loop grooming pattern as 0b038f1 (§9.2 update for
#000035 Phase 1): the analysis doc already named the test path
in §9.1 but did not yet point at the artifacts that just shipped.
This commit closes the loop for §9.1 + updates §11 status block.

Phase 1b (the actual v7-checkpoint measurement that resolves the
open question and feeds C_B1 tightening per #000043) still parks
on v7 deployment ramp-up — same exogenous gate as #000035 Phase 2.

Doc-only update; no schema, no governance hash, no code change.
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russell@unturf.com 2026-05-10 13:11:39 -04:00
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24
docs/soft-hash-channel-analysis.md
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@ -385,6 +385,23 @@ The reduction in §4 leaves three loose threads:
spectrum of `W^T W` and compare to typical Hessian eigenvalue
distributions on representative checkpoints.
**Phase 1a landed 2026-05-10** under #000034: synthetic-
ablation infrastructure at `bench/scripts/phi_alignment_probe.py`
(`measure_alignment(W, hessian_eval, *, k_top, k_bot, epsilon)
→ AlignmentReport`; Lanczos top-k + bottom-k via
`scipy.sparse.linalg.eigsh`). 14 tests in
`tests/test_phi_alignment_probe.py` covering verdict
classification (`STRUCTURAL_ALIGNMENT`, `NO_ALIGNMENT`,
`ANTI_ALIGNED`), boundary cases, and KAT regression. KAT
fixture at `bench/fixtures/phi-alignment/synthetic-checkpoints.jsonl`
pins synthetic-checkpoint verdicts so the probe is regression-
guarded ahead of v7 deployment ramp-up. Lands under
`bench/scripts/` (measurement tool, not a substrate primitive
like `arborist/substrate/anchor_prg.py`). **Phase 1b** runs
the probe against a real v7 checkpoint when one becomes
available; the alignment-score distribution then resolves
this open question and feeds C_B1 tightening per #000043.
2. **PRG modeling for `φ_PRG`.** The §4 reduction treats `φ_PRG`
as a random oracle. In practice it's a deterministic PRG with
public seed. The reduction holds modulo PRG security; we
@ -441,8 +458,11 @@ The reduction in §4 leaves three loose threads:
## 11. Status
**Open questions:** §9.1 (Hessian alignment under `φ_linear`,
parks on v7 deployment per #000034 Phase 1b),
**Open questions:** §9.1 (Hessian alignment under `φ_linear`:
synthetic-ablation infrastructure landed 2026-05-10 per #000034
Phase 1a — probe + 14 tests + KAT fixture; parks on v7
deployment data per #000034 Phase 1b for the actual checkpoint
measurement),
§9.2 (PRG cryptographic strength for `φ_PRG`: decision pinned +
Phase 1 reference implementation landed 2026-05-10 per #000035 —
HMAC-SHA-512 with 32-byte committed seed, KAT-pinned; awaits v7