Tooling: 2.07× faster shared-point verify digests with identical receipts

[VictorLiwentao]

Change and scope

At base 0b1cccf86e2f5132ed286a26ef0a681a495740ea, SharedPointCircuit.verify builds circuit_sha256 with per-active-node and per-partial-output json.dumps(..., separators=(',',':')) updates. Profiling on the historical full-size circuit (h=46) shows about half of verify wall time in that JSON encoder path. Open CrocSwap/integer-mult-bounds#1984 left this object as an explicit next question after shipping mixed-point scalar_check digests.

This PR writes the same UTF-8 digest lines with an equivalent hand-rolled formatter ([node,null,null], [node,[a,b],[common,local]], [common,[t0,t1,t2],node]), keeps every support and topology assertion, and leaves circuit_sha256 unchanged. The bit-compression certificate does not list scripts/shared_point_circuit.py in source_sha256.

Tooling improvement; no new kappa. Selected frontier untouched.

Result

On Linux / CPython 3.12.3 (Linux-6.12.94+-x86_64-with-glibc2.39), five alternating fresh-process pairs timing only SharedPointCircuit(46).verify (construction excluded; nested ExclusionCircuit.verify included) gave median wall time 2.212 → 1.070 seconds (2.07×). Timing is host-descriptive and is not a correctness gate. Every verify receipt matches the baseline checker fieldwise (roles, additions, merged_additions, circuit_sha256, flags).

Package: research/shared-point-digest/.

Validation

python3.12 -I -B research/shared-point-digest/verify.py
python3.12 -I -O -B research/shared-point-digest/verify.py
python3.12 -B scripts/research_package.py --package research/shared-point-digest
python3.12 -I -B research/shared-point-digest/benchmark.py --rounds 5

Expected:

PASS_SHARED_POINT_DIGEST verify_cases=5 encoding_cases=8 certs=0 no_new_kappa
PASS_REGISTERED_RESEARCH_PACKAGE research/shared-point-digest outcome=completed
PASS_IDENTICAL_SHARED_POINT_DIGEST_RECEIPTS

Default verify is read-only. Historical support checks use assert and are stripped under -O; circuit_sha256 identity remains the gate. Full make verify, selected cold replay, Lean, and multiplication-theorem obligations were not rerun for this isolated historical-checker change.

Overlap and credit

Closest priors (different objects): CrocSwap/integer-mult-bounds#756, CrocSwap/integer-mult-bounds#1793, CrocSwap/integer-mult-bounds#1861, CrocSwap/integer-mult-bounds#1922, CrocSwap/integer-mult-bounds#1984 (mixed-point scalar_check; this package answers its SharedPoint open question), CrocSwap/integer-mult-bounds#1874. No competing open PR on the SharedPointCircuit.verify digest object at refresh.

Douglas R. Colkitt authored the shared-point / exclusion circuits and bit-compression screens. Prepared by Wentao Li (VictorLiwentao, @Is__Victor) with substantial AI assistance, under Apache-2.0.

[Mister-Meeseeks]

Batch review at c5ba9f7b37b7e197c3faf5501d1c2f427d2972ab.

Merged to main, preserving the original contributor commits and package attribution.

Reviewed scope: Common-centre scalar digest optimization reproduces prior canonical digest/payloads across five ground sizes and complete encoding regression cases. Checks run with assertions enabled and optimized. Applies to valid constructed leaves; no frontier change or independently certified benchmark ratio.

The pinned scoped command passed; the batch ledger contains its command, input hashes, environment and log. This incorporates the research/tooling contribution and does not change the selected κ or discharge the inherited multiplication-theorem assumptions.

Batch review, attribution and evidence. Thank you for the contribution.