{ "number": 36475, "repo": "bitcoin/bitcoin", "url": "https://github.com/bitcoin/bitcoin/pull/36475", "title": "bench: add BIP-352 pubkey extraction benchmarks (standard + P2PKH worst-case)", "author": "theStack", "author_association": "MEMBER", "created_at": "2026-10-08T14:30:11Z", "updated_at": "2026-10-21T07:37:27Z", "description_hash": "d14d4db9ff29cef7", "age_days": 24, "draft": false, "labels": [ "Tests" ], "milestone": null, "base": "master", "head_sha": "56c0f168d1a81b19e4cd71ef81e7ce2d9c1624e3", "head_ref": "bip352-bench-pubkey_extraction", "head_repo": "theStack/bitcoin", "head_history": [ { "t": "2026-10-08T14:36:13Z", "sha": "747514aeb45271219e38ef0e091fe9a3300b4a0e" }, { "t": "2026-10-10T16:17:17Z", "sha": "d14be50b1140cb7df7745048a3fe0f826be6a37b" }, { "t": "2026-10-10T16:25:31Z", "sha": "457bb990c52e70b07ced2e3476573f8532911d6b" }, { "t": "2026-10-10T16:34:14Z", "sha": "56c0f168d1a81b19e4cd71ef81e7ce2d9c1624e3" } ], "additions": 112, "deletions": 0, "changed_files": 2, "commit_count": 2, "size_bucket": "M", "mergeable_state": "unknown", "bot": { "drahtbot": { "present": true, "reviews": { "ack": [ { "login": "Yudis-bit", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6233551410" }, { "login": "fametrano", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6310687100" } ], "concept_ack": [ { "login": "w0xlt", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6065831573" } ] }, "conflicts": [] } }, "acks_parsed": { "w0xlt": { "kind": "concept_ack", "hash": null, "t": "2026-10-08T17:52:20Z", "stale": false } }, "acks_tally": { "ack": 0, "stale_ack": 0, "concept_ack": 1, "approach_ack": 0, "nack": 0, "concept_nack": 0, "approach_nack": 0 }, "reviews": { "approved": 0, "changes_requested": 0, "distinct_reviewers": [ "Yudis-bit", "fametrano", "w0xlt" ] }, "signals": { "needs_rebase": false, "ci_failed": false, "mergeable_state": "unknown", "last_author_activity": "2026-10-10T17:07:26Z", "last_reviewer_activity": "2026-10-21T07:37:23Z", "last_reviewer": "fametrano", "author_silent_days": 22, "waiting_on_author_days": 11, "days_since_update": 11 }, "refs": { "mentioned": [ 36338, 36417 ], "depends_on": [], "fixes": [], "linked_issues": [], "references": [ { "number": 36338, "type": "pull", "state": "closed", "merged": true, "merged_at": "2026-10-07", "title": "BIP-352: fix P2PKH pubkey extraction from malleated scriptSig" }, { "number": 36417, "type": "pull", "state": "closed", "merged": false, "merged_at": null, "title": "bip352: verify redeem script and pubkey hash in GetPubKeyFromInput" } ], "conflicts": [] }, "stack": { "shares_commits_with": [], "based_on": [], "base_for": [] }, "review_paths": [], "body": "As there are ongoing changes to the Silent Payments public key extraction function `GetPubKeyFromInput` (see recently merged #36338, upcoming #36417), it seems reasonable to add benchmarks for it. The first commit covers the standard shape of each eligible input type (P2PKH, P2SH-P2WPKH, P2WPKH and P2TR script-path spend; see [BIP-352](https://github.com/bitcoin/bips/blob/master/bip-0352.mediawiki#user-content-Inputs_For_Shared_Secret_Derivation)). The second adds a worst-case P2PKH input with a maximally malleated scriptSig, where every push has to be hashed during the scan.\n\nResults on my arm64 machine (as per `$ ./build/bin/bench_bitcoin -filter='BIP352_.*'`):\n\n| ns/input | input/s | err% | total | benchmark\n|--------------------:|--------------------:|--------:|----------:|:----------\n| 3,034.12 | 329,584.35 | 0.2% | 0.01 | `BIP352_GetPubKey_P2PKH`\n| 69,868.20 | 14,312.66 | 0.1% | 0.01 | `BIP352_GetPubKey_P2PKH_WorstCase`\n| 2,841.35 | 351,945.44 | 0.1% | 0.01 | `BIP352_GetPubKey_P2SH_P2WPKH`\n| 2,768.00 | 361,272.01 | 0.1% | 0.01 | `BIP352_GetPubKey_P2TR`\n| 2,757.57 | 362,637.66 | 0.0% | 0.01 | `BIP352_GetPubKey_P2WPKH`", "commits": [ { "sha": "d71bc7127f0ce06da96476456160799e817f0a14", "date": "2026-10-09T17:38:13Z", "message": "bench: add benchmarks for BIP-352 pubkey extraction (standard inputs)\n\nBenchmark the public key extraction (`GetPubKeyFromInput`) for the\nstandard shape of each Silent Payments eligible input type, i.e.\nP2PKH, P2SH-P2WPKH, P2WPKH and P2TR. For P2TR, a script-path spend is\nused, as it runs all of the key-path extraction logic plus the control\nblock checks and the NUMS-H internal key comparison." }, { "sha": "56c0f168d1a81b19e4cd71ef81e7ce2d9c1624e3", "date": "2026-10-10T16:33:55Z", "message": "bench: add worst-case P2PKH benchmark for BIP-352 pubkey extraction\n\nAdd a P2PKH input with a malleated scriptSig that prepends as many\n33-byte pushes as the consensus scriptSig size limit (MAX_SCRIPT_SIZE)\nallows, each of which has to be hashed during the scan, followed by the\nactual signature and public key. The input respects all other consensus\nlimits (data pushes don't count towards MAX_OPS_PER_SCRIPT, the stack\nstays below MAX_STACK_SIZE), but is non-standard as it exceeds\nMAX_STANDARD_SCRIPTSIG_SIZE.\n\nResults on my arm64 machine:\n```\n$ ./build/bin/bench_bitcoin -filter='BIP352_.*'\n[...]\n\n| ns/input | input/s | err% | total | benchmark\n|--------------------:|--------------------:|--------:|----------:|:----------\n| 3,021.72 | 330,937.16 | 0.1% | 0.01 | `BIP352_GetPubKey_P2PKH`\n| 69,754.07 | 14,336.08 | 0.1% | 0.01 | `BIP352_GetPubKey_P2PKH_WorstCase`\n| 2,839.92 | 352,122.64 | 0.2% | 0.01 | `BIP352_GetPubKey_P2SH_P2WPKH`\n| 2,756.93 | 362,722.60 | 0.1% | 0.01 | `BIP352_GetPubKey_P2TR`\n| 2,752.45 | 363,312.34 | 0.0% | 0.01 | `BIP352_GetPubKey_P2WPKH`\n\n```" } ], "timeline": [ { "t": "2026-10-08T14:36:13Z", "kind": "force_push", "who": "theStack", "commit": "747514aeb45271219e38ef0e091fe9a3300b4a0e", "id": "push:747514aeb45271219e38ef0e091fe9a3300b4a0e" }, { "t": "2026-10-08T17:52:20Z", "kind": "comment", "who": "w0xlt", "assoc": "CONTRIBUTOR", "text": "Concept ACK", "id": "c:6065831573", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6065831573", "hash": "e8334cc43879b73c", "edited": null }, { "t": "2026-10-09T02:53:47Z", "kind": "comment", "who": "Yudis-bit", "assoc": "NONE", "text": "Concept and approach ACK.\n\nNumbers make sense given that `IsFullyValid()` point validation dominates the standard paths. In `P2PKH_WorstCase`, hoisting `pubkey_candidate` outside the while loop in `GetPubKeyFromInput` would save ~290 heap reallocations across the dummy pushes.\n\nIt might also be worth adding `P2TR_ScriptPath` and `P2TR_ScriptPath_NUMS` to benchmark the control-block validation and the early rejection path.", "id": "c:6073283486", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6073283486", "hash": "9e14cfbf47fb6ced", "edited": "2026-10-09T03:07:49Z" }, { "t": "2026-10-10T16:17:17Z", "kind": "force_push", "who": "theStack", "commit": "d14be50b1140cb7df7745048a3fe0f826be6a37b", "id": "push:d14be50b1140cb7df7745048a3fe0f826be6a37b" }, { "t": "2026-10-10T16:25:31Z", "kind": "force_push", "who": "theStack", "commit": "457bb990c52e70b07ced2e3476573f8532911d6b", "id": "push:457bb990c52e70b07ced2e3476573f8532911d6b" }, { "t": "2026-10-10T16:34:14Z", "kind": "force_push", "who": "theStack", "commit": "56c0f168d1a81b19e4cd71ef81e7ce2d9c1624e3", "id": "push:56c0f168d1a81b19e4cd71ef81e7ce2d9c1624e3" }, { "t": "2026-10-10T17:07:26Z", "kind": "comment", "who": "theStack", "assoc": "MEMBER", "text": "[quoted text omitted]\n\nDue to the strong similarity I think it's fine to have only a single representative P2TR benchmark, but I switched the one from key-path to script-path spending as the pubkey extraction contains (slightly) more logic. Also fixed the IWYU CI error. Thanks for the review!", "id": "c:6100051112", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6100051112", "hash": "0a28be284cbfde7f", "edited": "2026-10-10T17:18:17Z" }, { "t": "2026-10-17T11:51:23Z", "kind": "comment", "who": "Yudis-bit", "assoc": "NONE", "text": "re-tACK 56c0f168d1\n\nMakes sense to stick to one P2TR case. Windows numbers:\n\n| ns/input | input/s | err% | total | benchmark\n|--------------------:|--------------------:|--------:|----------:|:----------\n| 4,660.44 | 214,571.81 | 0.2% | 0.01 | `BIP352_GetPubKey_P2PKH`\n| 81,266.67 | 12,305.17 | 0.2% | 0.01 | `BIP352_GetPubKey_P2PKH_WorstCase`\n| 4,624.56 | 216,236.72 | 0.4% | 0.01 | `BIP352_GetPubKey_P2SH_P2WPKH`\n| 4,330.00 | 230,946.88 | 0.6% | 0.01 | `BIP352_GetPubKey_P2TR`\n| 4,335.53 | 230,652.50 | 0.2% | 0.01 | `BIP352_GetPubKey_P2WPKH`", "id": "c:6233551410", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6233551410", "hash": "73844640dee4809c", "edited": null }, { "t": "2026-10-21T07:37:23Z", "kind": "comment", "who": "fametrano", "assoc": "CONTRIBUTOR", "text": "tACK 56c0f168d1\n\nThe five benchmarks build and run on an Apple M5 (Release build, `bench_bitcoin -filter='BIP352_.*' -min-time=2000`, three runs). The four standard inputs take 2.2-2.6 \u00b5s each. The worst case, a 10,000-byte P2PKH scriptSig with 291 dummy pushes, takes 39-43 \u00b5s. I also rebuilt the five input shapes independently. A separate BIP352 implementation (btclib-wallet) extracts the expected key from each.", "id": "c:6310687100", "url": "https://github.com/bitcoin/bitcoin/pull/36475#issuecomment-6310687100", "hash": "9ef116da8389680b", "edited": null } ], "labels_log": [ { "t": "2026-10-08T14:30:16Z", "action": "labeled", "label": "Tests", "who": "DrahtBot" }, { "t": "2026-10-08T14:37:12Z", "action": "labeled", "label": "CI failed", "who": "DrahtBot" }, { "t": "2026-10-10T17:32:31Z", "action": "unlabeled", "label": "CI failed", "who": "DrahtBot" } ], "state_log": [], "text_chars": 4897, "text_tokens_estimate": 1224, "changed_paths": [ "src/bench/CMakeLists.txt", "src/bench/bip352.cpp" ], "files": [ { "path": "src/bench/CMakeLists.txt", "add": 1, "del": 0 }, { "path": "src/bench/bip352.cpp", "add": 111, "del": 0 } ], "test_lines": 112, "git": { "head": "56c0f168d1a81b19e4cd71ef81e7ce2d9c1624e3", "head_matches_backup": true, "base": "8406af1c0d69fa3ad4d50abb5d329354ad81445b", "patch_id": "d854c47c109ed677", "commits": [ { "sha": "d71bc7127f", "subject": "bench: add benchmarks for BIP-352 pubkey extraction (standard inputs)", "files": 2, "add": 86, "del": 0 }, { "sha": "56c0f168d1", "subject": "bench: add worst-case P2PKH benchmark for BIP-352 pubkey extraction", "files": 1, "add": 26, "del": 0 } ], "patch_truncated": false }, "patch_id": "d854c47c109ed677", "input_hash": "b8f54b0e1219e41a", "extracted_at": "2026-11-02T01:09:49+00:00" }