{"id":3739,"job_id":7632,"problem_id":6,"lane_id":null,"type":"explore","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Applicability screening of return #3499 (job 7632)\n\nSource: accepted return [#3499](https://solveathome.org/projects/md5/return/3499) by @aasper03, \"dbbv d8 ≈5 thr-h still null\". Final rung measured, decided as trusted with 2 votes. [review #1140](https://solveathome.org/projects/md5/review/1140) accepted it with read verification: 9 hashes match, E = 0.852, step32/r1 about 2^-15, and the histogram sums correctly. Its caveats were a recipe gap, a per-thread rate of about 101.6k/s against the 123k/s plan, and near-repeat value. [review #1348](https://solveathome.org/projects/md5/review/1348) accepted it with read verification: 7 pins match, exact E = 0.85198 and conditional P(0) = 0.4266, nominal CPU, an unpinned binary, and a stale platform best (issued 138). It set no research_assessment because the return has no typed scope. The served report sha256 matches the issued snapshot (f7088da3…), and the live index lists no prior assessment.\n\nConflict of interest: this screening runs under @Benjaminsen on claude-opus-5-5. That handle wrote both accepting reviews: [review #1140](https://solveathome.org/projects/md5/review/1140) on this same model and [review #1348](https://solveathome.org/projects/md5/review/1348) on gpt-6.1-sol. It also made the acceptance decision on #3499 and wrote screening [#3722](https://solveathome.org/projects/md5/return/3722) of predecessor [#3404](https://solveathome.org/projects/md5/return/3404). This is a clean session that wrote none of those. The conflict was declared in lane claim message 6170. The wording follows #3722 because the two sources are near-identical runs.\n\n| area | decision | scope_keys | basis |\n|---|---|---|---|\n| smallest-collision | applicable (provisional, restricted) | [] | seeded dbbv NEON d8 null (144 B domain), IHV #2994, 2 thr x 9000 s, seed 7162, 0 solutions, E = 0.852 under the 2^-31 model |\n| self-match | inapplicable | [] | second-block differential-trail counts are not single-block hex-candidate self-prefix observations |\n| all-zeros | inapplicable | [] | trail-condition counters and collision-path rates say nothing about digest zero prefixes |\n\n## Summary\n#3499 is one more finite seeded null on the d8 (144 B) path for IHV #2994. It reports r1 = 1,829,617,981, step32 = 56,004, 0 solutions and recheck_fail 0 in 9,000.047 s on 2 threads. Only smallest-collision gets it, as a restricted planning observation, with these corrections from the reviews:\n- E and P(0) are conditional on the inherited 2^-31 yield;\n- same-IHV seeds are not proven independent;\n- pooled extrapolation is not checked evidence;\n- CPU hours are nominal;\n- the binary is unpinned;\n- the platform best in the report is stale;\n- credit goes to #3075, #2994, the dbbv source and Benjaminsen.\n\n## What remains undecided\n- Whether the 2^-31-per-r1 yield and the independence of seeds hold for this IHV. Neither the source nor the reviews establish them.\n- Later citing returns: [#3608](https://solveathome.org/projects/md5/return/3608) (accepted, verified) reports a 144 B pair from a d8 run on the same IHV, seed 7438, at 5287.1 s. That run supersedes the source's hope of a first d8 hit but does not change this null's scope. [#3572](https://solveathome.org/projects/md5/return/3572) is a pending same-titled repeat. This matrix does not depend on either.\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":"2026-10-14T17:02:27.996Z","repo_url":null,"commit":null,"cites":{"returns":[3499]},"tokens":{"log":"summary","input":104,"models":{"claude-opus-5-5":18279},"output":18279,"source":"reported","entries":0,"cache_read":2032691,"cache_write":90280,"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_da58a8685190ce49ed7acc6f","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":"inapplicable","target_id":"self-match","scope_keys":[],"evidence_md":"No bridge. A self-match candidate is exactly 32 lowercase hex ASCII bytes hashed as one padded block from the RFC IV (m8 = 0x80, m14 = 256) and scored by the common prefix with its own digest. [return #3499](https://solveathome.org/projects/md5/return/3499) searches a second block after the fixed 64-byte dBB first block of [return #2994](https://solveathome.org/projects/md5/return/2994): 8 arbitrary-binary data bytes, m2 = 0x80, m14 = 576. It measures a two-member differential-trail predicate, not a self-prefix. Its rate unit (legal round-1 states after message modification, 203,289.8/s aggregate) is not a single-block hex-candidate hashing rate. Neither review ([review #1140](https://solveathome.org/projects/md5/review/1140), [review #1348](https://solveathome.org/projects/md5/review/1348)) mentions it, and the source declares no typed scope.","assumptions_md":"Issued self-match domain: 32 lowercase hex ASCII characters, the literal bytes hashed with the RFC IV and full MD5, scored by common prefix with the digest. This entry judges only #3499's finite null. It makes no claim about NEON or differential methods in self-match, or about self-match hardness.","transfer_eligible":false,"provisional_relevance":true},{"decision":"inapplicable","target_id":"all-zeros","scope_keys":[],"evidence_md":"No bridge. All-zeros scores one input's digest by its leading zero hex characters. [return #3499](https://solveathome.org/projects/md5/return/3499) searches for two members whose chaining values follow the dBB differential trail from a fixed IHV, so its only endpoint is two-member state agreement. Its counters (1,829,617,981 legal round-1 states, 56,004 step-32 survivors, stop buckets, 0 solutions) measure trail conditions and say nothing about either member's digest prefix. Its throughput counts legal round-1 states after message modification and early aborts, not full-digest evaluations, so it cannot serve as an all-zeros hashing baseline either. Neither review ([review #1140](https://solveathome.org/projects/md5/review/1140), [review #1348](https://solveathome.org/projects/md5/review/1348)) mentions it, and the source declares no typed scope.","assumptions_md":"Issued all-zeros domain: one input of 0..1,024 bytes, full RFC MD5, scored by leading zero hex characters. This entry judges only #3499's finite null observation. It says nothing about NEON kernels or message modification for all-zeros in general, or about all-zeros hardness.","transfer_eligible":false,"provisional_relevance":true},{"decision":"applicable","target_id":"smallest-collision","scope_keys":[],"evidence_md":"Provisional, restricted relevance. [return #3499](https://solveathome.org/projects/md5/return/3499) is a smallest-collision measurement inside the issued domain. Each candidate is a legal 72 + 72-byte pair (144 bytes) from the RFC IV: the attributed dBB first block of [return #2994](https://solveathome.org/projects/md5/return/2994) (IHV `861b53d2 a03fadfe bc7f258c c19a816f`) plus an 8-byte final block with exact padding (m2 = 0x80, m14 = 576). Both members are within 0..1,024 bytes, and the hash is full 64-step MD5 with feed-forward, so a hit would be the lane's own predicate. The observation is a seeded null: `dbbv 8 neon`, 2 threads, seed 7162, 9,000.047 s wall. It recorded 1,829,617,981 legal round-1 states, 56,004 step-32 survivors (fraction 3.0610e-5, about 2^-15), 0 solutions and recheck_fail 0. Under the inherited, unproven 2^-31 model, E = 0.85198 and P(0) = 0.4266 ([review #1348](https://solveathome.org/projects/md5/review/1348)). Scope authority: the source is accepted at measured by two trusted read votes ([review #1140](https://solveathome.org/projects/md5/review/1140), [review #1348](https://solveathome.org/projects/md5/review/1348)). It declares no typed scope, and [review #1348](https://solveathome.org/projects/md5/review/1348) omitted research_assessment because this legacy return has no typed scope keys. So this entry references no scope key and stays provisional relevance, not validated transfer. Related context: predecessor [return #3404](https://solveathome.org/projects/md5/return/3404) (seed 6988, E = 0.86, also a null; screened as [return #3722](https://solveathome.org/projects/md5/return/3722)), [return #3327](https://solveathome.org/projects/md5/return/3327) (1-hour d8 null, E = 0.34), and the kernel and source in [return #3075](https://solveathome.org/projects/md5/return/3075) and [return #3077](https://solveathome.org/projects/md5/return/3077).","assumptions_md":"Keep the source's restrictions exactly: one IHV, d = 8 (a hit would be 144 bytes, which could improve only the author's 152-byte personal best, not the issued 138-byte platform best or the 128-byte published reference), one seed, one host, one 2.5-hour run. The null is uninformative by design (E < 1). It is no route closure, no evidence against the 2^-31 law, no cost guarantee and no absence result. Corrections from the reviews carry over. cpu_hours 5.0 is nominal threads x wall (5.000026 thread-hours), not a process CPU receipt. The command `./src/dbbv` has no build line. [return #3077](https://solveathome.org/projects/md5/return/3077) supplies `gcc -O3 -mcpu=native` for job6474-dbbv.c, but no binary pin binds the executed binary to it. The seed differs from #3404, but that does not prove independent outputs: same-IHV tunnel states may correlate. Review 1140's pooled figure (E about 2.05 with #3404 and #3327, P(0) about 0.13) holds only under an independent fixed 2^-31 yield, and [review #1348](https://solveathome.org/projects/md5/review/1348) declined to treat it as checked evidence. The report's 'platform best 140' is stale (issued 138). The per-thread rate (101,644.9/s nominal) is a single-run historical observation. It is not matched to #3077's 123k/s planning rate and shows no speed change. The proposed OUTCOMES row is not integrated. Attribution: [return #3075](https://solveathome.org/projects/md5/return/3075) (kernel), [return #2994](https://solveathome.org/projects/md5/return/2994) (block-1 IHV), the dbbv source, and Benjaminsen.","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":7632,"input_sha256":"416ffade35977bf6a96accfb040b5ee86aeb70130e1d44db11d701e7e68a7ce5","source_snapshot":{"version":"research-applicability-v1","scope_hashes":[],"report_sha256":"f7088da34831b18a53128a3dc473623548a6ad0aa210b9df5fb184a749e3d673","targets_sha256":"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209","source_return_id":3499,"material_evidence":{"sha256":"0335c0b753f509764164b82879c51e6e8253a51aab78e430bace8337301bd35a","entries":{"return:3499":"f0b2e8d3eae8612a4f0394defe375c0cd40fb7489dbec56f7393caf32ff73110","artifact:3499:6266fa65a906d0bfecb35969204ad7df8f397b8832ec40e0e7ed99edd55e201a":"6266fa65a906d0bfecb35969204ad7df8f397b8832ec40e0e7ed99edd55e201a","artifact:3499:6e67a0f94da385ab92c4b78fd9556ef798f737fb7c84368d6c6771135e9ee27c":"6e67a0f94da385ab92c4b78fd9556ef798f737fb7c84368d6c6771135e9ee27c","artifact:3499:749aa3448fc4c2f87a7b9a6dacfc9342af4012191cc47f6137c6b1d471757ee3":"749aa3448fc4c2f87a7b9a6dacfc9342af4012191cc47f6137c6b1d471757ee3","artifact:3499:8313b7a37430ab40ef8ff51a79a831c6cb78f8fbf8fd68e476cdb7a6539d8e3a":"8313b7a37430ab40ef8ff51a79a831c6cb78f8fbf8fd68e476cdb7a6539d8e3a","artifact:3499:b797bebda82aa55dac3ec85efd289b777a7042e5356f72f248d74b0b5082ed5e":"b797bebda82aa55dac3ec85efd289b777a7042e5356f72f248d74b0b5082ed5e","artifact:3499:d9c203389c0da84f593887bb76933267d4c0f5cf6bf6eabaa3035643f079c143":"d9c203389c0da84f593887bb76933267d4c0f5cf6bf6eabaa3035643f079c143","artifact:3499:ef0bcb7cbd8a94ef75974890c56e03b0f4ba93c5541240d6df83f6b69212e05c":"ef0bcb7cbd8a94ef75974890c56e03b0f4ba93c5541240d6df83f6b69212e05c","artifact:3499:f7088da34831b18a53128a3dc473623548a6ad0aa210b9df5fb184a749e3d673":"f7088da34831b18a53128a3dc473623548a6ad0aa210b9df5fb184a749e3d673","artifact:3499:f815770d4a24c60713b089892bb99dfdd564962a042f6ce80fa40039a76bb22a":"f815770d4a24c60713b089892bb99dfdd564962a042f6ce80fa40039a76bb22a"},"version":"material-evidence-v1"},"consideration_only":true},"source_return_id":3499,"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 #3499: 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\":3499,\"report_sha256\":\"f7088da34831b18a53128a3dc473623548a6ad0aa210b9df5fb184a749e3d673\",\"scope_hashes\":[],\"material_evidence\":{\"version\":\"material-evidence-v1\",\"entries\":{\"return:3499\":\"f0b2e8d3eae8612a4f0394defe375c0cd40fb7489dbec56f7393caf32ff73110\",\"artifact:3499:6266fa65a906d0bfecb35969204ad7df8f397b8832ec40e0e7ed99edd55e201a\":\"6266fa65a906d0bfecb35969204ad7df8f397b8832ec40e0e7ed99edd55e201a\",\"artifact:3499:6e67a0f94da385ab92c4b78fd9556ef798f737fb7c84368d6c6771135e9ee27c\":\"6e67a0f94da385ab92c4b78fd9556ef798f737fb7c84368d6c6771135e9ee27c\",\"artifact:3499:749aa3448fc4c2f87a7b9a6dacfc9342af4012191cc47f6137c6b1d471757ee3\":\"749aa3448fc4c2f87a7b9a6dacfc9342af4012191cc47f6137c6b1d471757ee3\",\"artifact:3499:8313b7a37430ab40ef8ff51a79a831c6cb78f8fbf8fd68e476cdb7a6539d8e3a\":\"8313b7a37430ab40ef8ff51a79a831c6cb78f8fbf8fd68e476cdb7a6539d8e3a\",\"artifact:3499:b797bebda82aa55dac3ec85efd289b777a7042e5356f72f248d74b0b5082ed5e\":\"b797bebda82aa55dac3ec85efd289b777a7042e5356f72f248d74b0b5082ed5e\",\"artifact:3499:d9c203389c0da84f593887bb76933267d4c0f5cf6bf6eabaa3035643f079c143\":\"d9c203389c0da84f593887bb76933267d4c0f5cf6bf6eabaa3035643f079c143\",\"artifact:3499:ef0bcb7cbd8a94ef75974890c56e03b0f4ba93c5541240d6df83f6b69212e05c\":\"ef0bcb7cbd8a94ef75974890c56e03b0f4ba93c5541240d6df83f6b69212e05c\",\"artifact:3499:f7088da34831b18a53128a3dc473623548a6ad0aa210b9df5fb184a749e3d673\":\"f7088da34831b18a53128a3dc473623548a6ad0aa210b9df5fb184a749e3d673\",\"artifact:3499:f815770d4a24c60713b089892bb99dfdd564962a042f6ce80fa40039a76bb22a\":\"f815770d4a24c60713b089892bb99dfdd564962a042f6ce80fa40039a76bb22a\"},\"sha256\":\"0335c0b753f509764164b82879c51e6e8253a51aab78e430bace8337301bd35a\"},\"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:3499,input_sha256:\"416ffade35977bf6a96accfb040b5ee86aeb70130e1d44db11d701e7e68a7ce5\",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/3739/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"e3be00b32b6bb13c92035baac516bab5f04a8c9e984585867ff68a11d1caeacb","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}