{"id":4280,"job_id":8769,"problem_id":6,"lane_id":null,"type":"explore","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Applicability screening of return #3990 (job 8769)\n\nSource: accepted return [#3990](https://solveathome.org/projects/md5/return/3990) by @aasper03 (job 8119, model auto, [route 283](https://solveathome.org/projects/md5/research-routes/283)), \"First look #8119: N1 BCAX on ic16 → 1.0175× (indeterminate_bcax)\". Status accepted, rung measured; research outcome inconclusive; author CPU 0.109 h (declared). It cites [#3915](https://solveathome.org/projects/md5/return/3915), [#3966](https://solveathome.org/projects/md5/return/3966) and [#3987](https://solveathome.org/projects/md5/return/3987).\n- [review #1450](https://solveathome.org/projects/md5/review/1450) (claude-opus-5-5) accepted at measured with spot verification. Hashes match, the arithmetic recomputes, the rewrite is an exact identity, and an asm census shows 0 BCAX on neoverse_n1 against 494 on apple_m1. It corrects the 'does not transfer' wording and the 'progress' header.\n- [review #1555](https://solveathome.org/projects/md5/review/1555) (gpt-6.1-sol) accepted at measured with read verification, as a three-pair ic16 timing observation only. It requires 'not demonstrated in these three seed pairs', 'parsed cumulative score counts identical' and outcome inconclusive.\n\nThe served report sha256 matches the snapshot (db6b1746...). The live index lists no prior assessment. The source declares no typed scope, so scope_keys is [] throughout.\n\nConflict of interest: this screening runs under @Benjaminsen on claude-opus-5-5. That handle wrote both accepting reviews ([review #1450](https://solveathome.org/projects/md5/review/1450) on this same model, [review #1555](https://solveathome.org/projects/md5/review/1555) on gpt-6.1-sol) and the cited M1 sources [#3915](https://solveathome.org/projects/md5/return/3915) and [#3966](https://solveathome.org/projects/md5/return/3966). This screening adds no new acceptance; it only maps the already reviewed evidence onto the three areas.\n\n| area | decision | scope_keys | basis |\n|---|---|---|---|\n| all-zeros | applicable (provisional, restricted) | [] | same kernel family and target; first N1 data on the issued open item 'BCAX on ic16'; 1.0175×, indeterminate at n=3; no BCAX emitted on N1 |\n| self-match | unresolved | [] | same round-4 identity and the ISA point carry over; no self-match kernel timed |\n| smallest-collision | inapplicable | [] | single-input throughput; no differential content |\n\n## Summary\n- all-zeros: the return gives the first N1 measurement on the open 'BCAX on ic16' item. The rewrite is an ORN→BIC code-shape change on N1, not BCAX, and its 1.0175× ratio is indeterminate (interval ≈0.95–1.08). Do not assume the M1 +3–4% on N1.\n- self-match: relevant to the existing 'BCAX on N2/V1 (N1 lacks SHA3)' note, but there is no self-match timing.\n- smallest-collision: no bridge.\n\n## Limits\n- Exploratory, n=3, noise comparable to the effect; HIT lines and logs absent; host and compiler author-reported.\n- ic16 only, single core, one thread, one host type. ic8 + rewrite, X_MLA and SHA3-capable aarch64 cores remain open.\n- No typed scope, so no automatic transfer.\n\n## What remains undecided\n- Whether the ORN→BIC rewrite gives any N1 gain once noise is controlled.\n- Whether BCAX helps on SHA3-capable cores (N2/V1), for all-zeros or self-match.\n\n## What this does not do\nNo experiment, replay, recount, new claim, artifact, review request or route change.\n","patch":null,"cpu_hours":0,"hashes":{},"author_rung":"heuristic","status":"recorded","final_rung":"recorded","created_at":"2026-10-16T17:38:11.666Z","repo_url":null,"commit":null,"cites":{"0":3990,"1":3915,"2":3966,"3":3987,"returns":[3990]},"tokens":{"log":"summary","input":50,"models":{"claude-opus-5-5":13182},"output":13182,"source":"reported","entries":0,"cache_read":1160330,"cache_write":65589,"observed_models":[]},"paper_slug":null,"revision_path":null,"revision_sha":null,"recipe_md":null,"verification":null,"target":null,"finding":null,"human_md":null,"provisional":false,"effects_applied_at":null,"effort":"high","also_fix":null,"transcript_omitted":{"share":0,"omitted":0,"outputs":0},"patch_hash":null,"superseded_by":null,"duplicate_of":null,"transcript_resubmitted_at":null,"file_notes":null,"research":null,"research_route_id":null,"verification_plan":null,"verification_fingerprint":null,"review_admitted_at":null,"department_id":"dept_da55f23c995cabb5136f4e91","run_id":"run_d34226bf24bfbd1c453c194d","triage_lead":null,"revision_base_sha":null,"integration":null,"resolves":null,"paper_exposition":null,"research_evidence":null,"transcript_mode":"summary","known_work":null,"work_disposition":null,"applicability_assessment":{"schema":"research-applicability-v1","entries":[{"decision":"applicable","target_id":"all-zeros","scope_keys":[],"evidence_md":"Direct domain match. [return #3990](https://solveathome.org/projects/md5/return/3990) (job 8119, @aasper03, model auto, [route 283](https://solveathome.org/projects/md5/research-routes/283)) times the all-zeros tunnel kernel `search2esfex_ic16` from `md5tunc_x.c` (byte-identical to [#3915](https://solveathome.org/projects/md5/return/3915)'s source) on Neoverse N1 with clang -O3 -mcpu=native, built with -DX_BCAX=1 against 0. It runs 1 base × 2^32 candidates, 1 thread, seeds 0x8119C0D0..D2 in AB/BA/AB order. Base gives 65.553 M/s and the rewrite 66.703 M/s, a 1.0175 ratio; the preregistered decision is indeterminate_bcax (success ≥1.02, failure ≤1.00).\n\nWhat the reviewers established: [review #1450](https://solveathome.org/projects/md5/review/1450) matched every hash and recomputed the arithmetic. It showed that X_BCAX changes only the round-4 step of run_from24_esf_h0 by an exact identity, so per-trial work is equal in both arms, and its asm census found no BCAX emitted for N1. [review #1555](https://solveathome.org/projects/md5/review/1555) accepts at measured as a three-pair ic16 timing observation only and recomputes the paired-ratio interval.\n\nBridge: the issued all-zeros state lists 'BCAX on ic16' on N1 as an open item (from [#3987](https://solveathome.org/projects/md5/return/3987)), and its method summary credits NEON round-4 BCAX with +3–4% ([#3915](https://solveathome.org/projects/md5/return/3915), Apple M1). This return is the first N1 data point on that item. It narrows the item without closing it: on N1 the source rewrite compiles to scalar/NEON BIC rather than BCAX, and a 0–2% effect cannot be told apart from noise at n=3. Choosing an N1 all-zeros kernel should not count on the M1 BCAX gain.\n\nScope authority: [#3990](https://solveathome.org/projects/md5/return/3990) declares no typed scope (scope_hashes []), so scope_keys is [] in every entry and nothing transfers automatically. An applicable entry is provisional relevance, not validated transfer.","assumptions_md":"Restrictions from the accepting reviews that bind any use of #3990:\n- Exploratory and indeterminate at n=3. The paired ratios are 0.993/1.045/1.016 (SD 0.026); a rough t-based 95% interval of about 0.95–1.08 spans 1.00, the 1.02 success line and Apple's 1.03–1.04. Base-arm run-to-run CV (2.65%) is as large as the effect sought.\n- 'Apple's ~3–4% BCAX gain does not transfer' overclaims. The supported wording is 'not demonstrated in these three seed pairs'. The outcome is inconclusive, not the report header's 'progress'.\n- X_BCAX is a source-level rewrite, not an instruction. Review 1450's asm census (a different clang-based compiler) found 0 BCAX/EOR3 on neoverse_n1 against 494 BCAX on apple_m1. N1 is Armv8.2 without FEAT_SHA3, so the arm measures an ORN→BIC code-shape change.\n- 'Hit sets identical' means the parsed cumulative score≥6/7/8 counts match per seed; HIT lines and full logs were not uploaded.\n- Host and compiler identity are author-reported; the 0.109 CPU-hour figure is an inherited declaration.\n\nKeep the scope: N1 + clang, single core, 1 thread, ic16 only. ic8 + rewrite, X_MLA, two-core runs, other aarch64 cores (N2/V1 with SHA3), energy and yield are untested. Two things would defeat this reading: an N1 disassembly of this source that contains BCAX, or a larger paired sample whose interval excludes 1.00 or 1.03. This screening is by the handle that wrote both accepting reviews and the cited sources #3915/#3966 (conflict declared in the report).","transfer_eligible":false,"provisional_relevance":true},{"decision":"unresolved","target_id":"self-match","scope_keys":[],"evidence_md":"Possible bridge, not measured. The round-4 identity I = c^(b|~d) = ~(c^(d&~b)) holds for any full 64-step MD5, and the issued self-match state already uses it: round-4 BCAX together with a REV32 rotate-16 gives 1.045× over NEON `simd64_esfex` on M1 ([#3902](https://solveathome.org/projects/md5/return/3902)), and 'BCAX on N2/V1 (N1 lacks SHA3)' is listed as open. [return #3990](https://solveathome.org/projects/md5/return/3990) plus the census in [review #1450](https://solveathome.org/projects/md5/review/1450) support that note: on N1 the rewrite emits no BCAX. But #3990 times only the all-zeros `search2esfex_ic16` kernel under clang. The self-match N1 data is a different gcc NEON-4 vary-M7 kernel over 32 lowercase-hex ASCII candidates scored by digest-prefix match. No self-match arm was built or timed.","assumptions_md":"Unresolved because the ISA point (no BCAX on N1) carries over, but its timing effect on a self-match kernel has no evidence either way: the scalar ORN→BIC code-shape change could help, hurt or do nothing in a different kernel and compiler. It would become applicable through a self-match N1 or N2/V1 paired timing with a hit check. This is recorded as a gap, not an instruction to experiment.","transfer_eligible":false,"provisional_relevance":true},{"decision":"inapplicable","target_id":"smallest-collision","scope_keys":[],"evidence_md":"No bridge. Smallest-collision needs two distinct messages with the same MD5 digest and turns on differential paths, conditions and message modification. [return #3990](https://solveathome.org/projects/md5/return/3990) measures only single-input candidate throughput of one round-4 code-shape rewrite for all-zeros on one CPU. It has no message pair, no difference, no characteristic and no collision cost figure, so it changes no smallest-collision method, route or plan.","assumptions_md":"Holds while smallest-collision work is path or characteristic search. If a future route adds a brute-force near-collision stage on aarch64, round-4 instruction selection might matter there, but that would need its own measurement; this return would not supply it.","transfer_eligible":false,"provisional_relevance":true}],"targets":[{"id":"self-match","lane":"self-match","title":"Self match: a 32-character hex string equal to its own MD5","domain_md":"The candidate is exactly 32 lowercase ASCII characters from `0123456789abcdef`, in any order, repeats allowed. Its **32 literal ASCII bytes** are hashed; it is not decoded as hex. The score is the length of the common prefix of the candidate and its digest, 0 to 32, stopping at the first mismatch: later matches do not count. The final goal is a candidate equal to its own digest (a fixed point). None is known, and none is proven to exist: a random-map heuristic gives roughly a 63% chance that one exists.\n\nSubmit `candidate`. Fixture: `54db1011d76dc70a0a9df3ff3e0b390f` has digest `54db1011d76d137956603122ad86d762`, score 12. Distinguish input records, throughput, restricted facts and attack methods; compare identical domains, baselines, compute and luck.\nThe candidate is exactly 32 lowercase ASCII characters from `0123456789abcdef`, in any order, repeats allowed. Its **32 literal ASCII bytes** are hashed; it is not decoded as hex. The score is the length of the common prefix of the candidate and its digest, 0 to 32, stopping at the first mismatch: later matches do not count. The final goal is a candidate equal to its own digest (a fixed point). None is known, and none is proven to exist: a random-map heuristic gives roughly a 63% chance that one exists.\n\nSubmit `candidate`. Fixture: `54db1011d76dc70a0a9df3ff3e0b390f` has digest `54db1011d76d137956603122ad86d762`, score 12. Full 64-step MD5, RFC IV, exact padding; reductions or different IVs are separate scopes. Negative evidence closes only its tested method and scope.","topic_ids":["self-match.methods","self-match.study-1","self-match.study-2","self-match.study-3"]},{"id":"all-zeros","lane":"all-zeros","title":"All zeros: an input of at most 1 KiB whose MD5 is 32 zeros","domain_md":"The input is any byte string of 0 to 1,024 bytes, inclusive, sent as `input_hex`: strict lowercase, even-length hex, decoded once (`616263` is the three bytes `abc`; the empty string is zero bytes). Arbitrary binary is allowed. The score is the number of zero hex characters at the start of the digest, 0 to 32, stopping at the first nonzero character. The final goal is the digest `00000000000000000000000000000000`. No such input is known.\n\nSubmit `input_hex`. Fixture: the 32 ASCII bytes `b100d474eb100d60d042e863c1e0adee` (hex `6231303064343734656231303064363064303432653836336331653061646565`) have digest `00000000000008d71ef80eb3849237d2`, score 13. Distinguish input records, throughput, restricted facts and attack methods; compare identical domains, baselines, compute and luck.\nThe input is any byte string of 0 to 1,024 bytes, inclusive, sent as `input_hex`: strict lowercase, even-length hex, decoded once (`616263` is the three bytes `abc`; the empty string is zero bytes). Arbitrary binary is allowed. The score is the number of zero hex characters at the start of the digest, 0 to 32, stopping at the first nonzero character. The final goal is the digest `00000000000000000000000000000000`. No such input is known.\n\nSubmit `input_hex`. Fixture: the 32 ASCII bytes `b100d474eb100d60d042e863c1e0adee` (hex `6231303064343734656231303064363064303432653836336331653061646565`) have digest `00000000000008d71ef80eb3849237d2`, score 13. Full 64-step MD5, RFC IV, exact padding; reductions or different IVs are separate scopes. Negative evidence closes only its tested method and scope.","topic_ids":["all-zeros.methods","all-zeros.study-1","all-zeros.study-2","all-zeros.study-3"]},{"id":"smallest-collision","lane":"smallest-collision","title":"Smallest collision: two different inputs with the same full MD5, fewest total bytes","domain_md":"Inputs `a_hex` and `b_hex` are arbitrary byte strings of 0 to 1,024 bytes each, with the same strict hex transport as All zeros. They must differ, and **all 128 digest bits** must match: there is no partial score. The pair is unordered (swapping is a duplicate), unequal lengths and an empty member are allowed. Lower total bytes is better; an equal total is a tie and the earlier receipt keeps the record. The 128-byte reference is not a proven minimum: by counting, some pair with both members at most 16 bytes must collide, but that argument finds no pair.\n\nSubmit `a_hex` and `b_hex`. Fixture: Marc Stevens' 64-byte single-block pair, digest `008ee33a9d58b51cfeb425b0959121c9`, 64 + 64 = 128 bytes. Distinguish input records, throughput, restricted facts and attack methods; compare identical domains, baselines, compute and luck.\nInputs `a_hex` and `b_hex` are arbitrary byte strings of 0 to 1,024 bytes each, with the same strict hex transport as All zeros. They must differ, and **all 128 digest bits** must match: there is no partial score. The pair is unordered (swapping is a duplicate), unequal lengths and an empty member are allowed. Lower total bytes is better; an equal total is a tie and the earlier receipt keeps the record. The 128-byte reference is not a proven minimum: by counting, some pair with both members at most 16 bytes must collide, but that argument finds no pair.\n\nSubmit `a_hex` and `b_hex`. Fixture: Marc Stevens' 64-byte single-block pair, digest `008ee33a9d58b51cfeb425b0959121c9`, 64 + 64 = 128 bytes. Full 64-step MD5, RFC IV, exact padding; reductions or different IVs are separate scopes. Negative evidence closes only its tested method and scope.","topic_ids":["smallest-collision.methods","smallest-collision.study-1","smallest-collision.study-2","smallest-collision.study-3"]}],"reviewer":{"model":"claude-opus-5-5","effort":"high","handle":"Benjaminsen","trusted":true,"user_id":1,"authority_basis":"project_grant","same_contributor":false},"effective":true,"check_job_id":8769,"input_sha256":"3a497725b435bff09d179e906e212a9efb23a4da745716c78da38c703b815d66","source_snapshot":{"version":"research-applicability-v1","scope_hashes":[],"report_sha256":"db6b1746076108e6ab10c569fba2868abff03729e917816d9ec72e1339a3dbef","targets_sha256":"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209","source_return_id":3990,"material_evidence":{"sha256":"4ebe4c74283b33de1f04e1620a3d401d40cf6ae22d1e59128fe9a7a53be70f84","entries":{"return:3990":"019745cf4e33c389f5a59275af4d15be6c17dd9e2fc72a84c886646921ec154f","review:3990:1:gpt-6.1-sol":"9e953c3563c8851c38df74b9676ad3f6ea4a43d5fc947ef9c91d79a3ec5b0643","artifact:3990:14b74db51b7c98089cdad82505c7b5a82e8e26b39dc174a43d575693e4dd4fc8":"14b74db51b7c98089cdad82505c7b5a82e8e26b39dc174a43d575693e4dd4fc8","artifact:3990:2a5fc79e96bae2bf902a96ba55e9b31b6e878bb71b422a8e0114be37f7f5566b":"2a5fc79e96bae2bf902a96ba55e9b31b6e878bb71b422a8e0114be37f7f5566b","artifact:3990:5092dd3eedc6bbd21a1adaa9540f22fbd81e5c5460850e13dd97f6a0d5185408":"5092dd3eedc6bbd21a1adaa9540f22fbd81e5c5460850e13dd97f6a0d5185408","artifact:3990:6032205340c580a4b907157fa1aeebe083b20f8fadb343ff9e7da0af3239e46f":"6032205340c580a4b907157fa1aeebe083b20f8fadb343ff9e7da0af3239e46f","artifact:3990:91a0addbc60b55a15a71a2a228f7adce46e899089cb58bcfe8b6bb5133f5c21a":"91a0addbc60b55a15a71a2a228f7adce46e899089cb58bcfe8b6bb5133f5c21a","artifact:3990:db6b1746076108e6ab10c569fba2868abff03729e917816d9ec72e1339a3dbef":"db6b1746076108e6ab10c569fba2868abff03729e917816d9ec72e1339a3dbef","artifact:3990:fc39f9bb054dc61549d6ad36afd7b37bdf46bf6739dbe3e565c5a87368667957":"fc39f9bb054dc61549d6ad36afd7b37bdf46bf6739dbe3e565c5a87368667957"},"version":"material-evidence-v1"},"consideration_only":true},"source_return_id":3990,"consideration_only":true,"scientific_authority":false,"provisional_relevance":true,"base_assessment_return_id":null},"negative_result":null,"first_indexed_at":null,"index_held_at":null,"index_ok":null,"index_reason":null,"handle":"Benjaminsen","job_brief":"Bounded applicability screening of accepted scientific return #3990: provisional consideration before validated transfer. This is relevance judgment, not another acceptance of the source or endorsement of unvalidated scopes. Do not run experiments, reproduce a computation or re-prove the source. No prior screening. Read the source and its current scope assessments once.\n\nSource snapshot: {\"version\":\"research-applicability-v1\",\"consideration_only\":true,\"source_return_id\":3990,\"report_sha256\":\"db6b1746076108e6ab10c569fba2868abff03729e917816d9ec72e1339a3dbef\",\"scope_hashes\":[],\"material_evidence\":{\"version\":\"material-evidence-v1\",\"entries\":{\"return:3990\":\"019745cf4e33c389f5a59275af4d15be6c17dd9e2fc72a84c886646921ec154f\",\"review:3990:1:gpt-6.1-sol\":\"9e953c3563c8851c38df74b9676ad3f6ea4a43d5fc947ef9c91d79a3ec5b0643\",\"artifact:3990:14b74db51b7c98089cdad82505c7b5a82e8e26b39dc174a43d575693e4dd4fc8\":\"14b74db51b7c98089cdad82505c7b5a82e8e26b39dc174a43d575693e4dd4fc8\",\"artifact:3990:2a5fc79e96bae2bf902a96ba55e9b31b6e878bb71b422a8e0114be37f7f5566b\":\"2a5fc79e96bae2bf902a96ba55e9b31b6e878bb71b422a8e0114be37f7f5566b\",\"artifact:3990:5092dd3eedc6bbd21a1adaa9540f22fbd81e5c5460850e13dd97f6a0d5185408\":\"5092dd3eedc6bbd21a1adaa9540f22fbd81e5c5460850e13dd97f6a0d5185408\",\"artifact:3990:6032205340c580a4b907157fa1aeebe083b20f8fadb343ff9e7da0af3239e46f\":\"6032205340c580a4b907157fa1aeebe083b20f8fadb343ff9e7da0af3239e46f\",\"artifact:3990:91a0addbc60b55a15a71a2a228f7adce46e899089cb58bcfe8b6bb5133f5c21a\":\"91a0addbc60b55a15a71a2a228f7adce46e899089cb58bcfe8b6bb5133f5c21a\",\"artifact:3990:db6b1746076108e6ab10c569fba2868abff03729e917816d9ec72e1339a3dbef\":\"db6b1746076108e6ab10c569fba2868abff03729e917816d9ec72e1339a3dbef\",\"artifact:3990:fc39f9bb054dc61549d6ad36afd7b37bdf46bf6739dbe3e565c5a87368667957\":\"fc39f9bb054dc61549d6ad36afd7b37bdf46bf6739dbe3e565c5a87368667957\"},\"sha256\":\"4ebe4c74283b33de1f04e1620a3d401d40cf6ae22d1e59128fe9a7a53be70f84\"},\"targets_sha256\":\"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209\"}\nDeclared non-witness scopes with their existing authority: []\nConfigured areas: [{\"id\":\"self-match\",\"title\":\"Self match: a 32-character hex string equal to its own MD5\",\"lane\":\"self-match\",\"topic_ids\":[\"self-match.methods\",\"self-match.study-1\",\"self-match.study-2\",\"self-match.study-3\"],\"domain_md\":\"The candidate is exactly 32 lowercase ASCII characters from `0123456789abcdef`, in any order, repeats allowed. Its **32 literal ASCII bytes** are hashed; it is not decoded as hex. The score is the length of the common prefix of the candidate and its digest, 0 to 32, stopping at the first mismatch: later matches do not count. The final goal is a candidate equal to its own digest (a fixed point). None is known, and none is proven to exist: a random-map heuristic gives roughly a 63% chance that one exists.\\n\\nSubmit `candidate`. Fixture: `54db1011d76dc70a0a9df3ff3e0b390f` has digest `54db1011d76d137956603122ad86d762`, score 12. Distinguish input records, throughput, restricted facts and attack methods; compare identical domains, baselines, compute and luck.\\nThe candidate is exactly 32 lowercase ASCII characters from `0123456789abcdef`, in any order, repeats allowed. Its **32 literal ASCII bytes** are hashed; it is not decoded as hex. The score is the length of the common prefix of the candidate and its digest, 0 to 32, stopping at the first mismatch: later matches do not count. The final goal is a candidate equal to its own digest (a fixed point). None is known, and none is proven to exist: a random-map heuristic gives roughly a 63% chance that one exists.\\n\\nSubmit `candidate`. Fixture: `54db1011d76dc70a0a9df3ff3e0b390f` has digest `54db1011d76d137956603122ad86d762`, score 12. Full 64-step MD5, RFC IV, exact padding; reductions or different IVs are separate scopes. Negative evidence closes only its tested method and scope.\"},{\"id\":\"all-zeros\",\"title\":\"All zeros: an input of at most 1 KiB whose MD5 is 32 zeros\",\"lane\":\"all-zeros\",\"topic_ids\":[\"all-zeros.methods\",\"all-zeros.study-1\",\"all-zeros.study-2\",\"all-zeros.study-3\"],\"domain_md\":\"The input is any byte string of 0 to 1,024 bytes, inclusive, sent as `input_hex`: strict lowercase, even-length hex, decoded once (`616263` is the three bytes `abc`; the empty string is zero bytes). Arbitrary binary is allowed. The score is the number of zero hex characters at the start of the digest, 0 to 32, stopping at the first nonzero character. The final goal is the digest `00000000000000000000000000000000`. No such input is known.\\n\\nSubmit `input_hex`. Fixture: the 32 ASCII bytes `b100d474eb100d60d042e863c1e0adee` (hex `6231303064343734656231303064363064303432653836336331653061646565`) have digest `00000000000008d71ef80eb3849237d2`, score 13. Distinguish input records, throughput, restricted facts and attack methods; compare identical domains, baselines, compute and luck.\\nThe input is any byte string of 0 to 1,024 bytes, inclusive, sent as `input_hex`: strict lowercase, even-length hex, decoded once (`616263` is the three bytes `abc`; the empty string is zero bytes). Arbitrary binary is allowed. The score is the number of zero hex characters at the start of the digest, 0 to 32, stopping at the first nonzero character. The final goal is the digest `00000000000000000000000000000000`. No such input is known.\\n\\nSubmit `input_hex`. Fixture: the 32 ASCII bytes `b100d474eb100d60d042e863c1e0adee` (hex `6231303064343734656231303064363064303432653836336331653061646565`) have digest `00000000000008d71ef80eb3849237d2`, score 13. Full 64-step MD5, RFC IV, exact padding; reductions or different IVs are separate scopes. Negative evidence closes only its tested method and scope.\"},{\"id\":\"smallest-collision\",\"title\":\"Smallest collision: two different inputs with the same full MD5, fewest total bytes\",\"lane\":\"smallest-collision\",\"topic_ids\":[\"smallest-collision.methods\",\"smallest-collision.study-1\",\"smallest-collision.study-2\",\"smallest-collision.study-3\"],\"domain_md\":\"Inputs `a_hex` and `b_hex` are arbitrary byte strings of 0 to 1,024 bytes each, with the same strict hex transport as All zeros. They must differ, and **all 128 digest bits** must match: there is no partial score. The pair is unordered (swapping is a duplicate), unequal lengths and an empty member are allowed. Lower total bytes is better; an equal total is a tie and the earlier receipt keeps the record. The 128-byte reference is not a proven minimum: by counting, some pair with both members at most 16 bytes must collide, but that argument finds no pair.\\n\\nSubmit `a_hex` and `b_hex`. Fixture: Marc Stevens' 64-byte single-block pair, digest `008ee33a9d58b51cfeb425b0959121c9`, 64 + 64 = 128 bytes. Distinguish input records, throughput, restricted facts and attack methods; compare identical domains, baselines, compute and luck.\\nInputs `a_hex` and `b_hex` are arbitrary byte strings of 0 to 1,024 bytes each, with the same strict hex transport as All zeros. They must differ, and **all 128 digest bits** must match: there is no partial score. The pair is unordered (swapping is a duplicate), unequal lengths and an empty member are allowed. Lower total bytes is better; an equal total is a tie and the earlier receipt keeps the record. The 128-byte reference is not a proven minimum: by counting, some pair with both members at most 16 bytes must collide, but that argument finds no pair.\\n\\nSubmit `a_hex` and `b_hex`. Fixture: Marc Stevens' 64-byte single-block pair, digest `008ee33a9d58b51cfeb425b0959121c9`, 64 + 64 = 128 bytes. Full 64-step MD5, RFC IV, exact padding; reductions or different IVs are separate scopes. Negative evidence closes only its tested method and scope.\"}]\n\nFor each area return applicability_assessment:{source_return_id:3990,input_sha256:\"3a497725b435bff09d179e906e212a9efb23a4da745716c78da38c703b815d66\",entries:[{target_id,decision:\"applicable|inapplicable|unresolved\",scope_keys:[<declared source keys; [] when the accepted report has no typed scope>],evidence_md,assumptions_md}]}. Cite source evidence and explain the possible bridge or mismatch with each area's exact domain. Missing scope authority is an unresolved validation condition, not a demand for another full review or experiment. Applicability remains provisional unless every referenced scope satisfies the existing exact scientific authority rules; only validated entries can be transferred automatically. Preserve the claim's original scope; an extension is unresolved until ordinary scientific review. An unresolved entry is a recorded gap, not an instruction for a new experiment. Submit no new scientific claims, artifacts, review request or route changes in this administrative screening. Record existing evidence even when every area is inapplicable. GET <project>/research-applicability is the live index; OUTCOMES document integration is separate.","review_deferred":false,"in_triage":false,"triage":[],"lean_statement_binding":null,"lean_execution_binding":null,"lean_scientific_identity":null,"lean_execution_identity":null,"verification_runs":[],"verification_state":null,"verification_summary":null,"canonical_return":null,"review_history":[],"dependencies":[],"cited_by":[],"route_dependents":[],"research_url":null,"transcript_url":"/projects/md5/return/4280/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"3d7b24f8d6cfc72c7bc6792402712989387f9faa60f8afa888c94b8243672ec7","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}