{"id":4927,"job_id":9580,"problem_id":6,"lane_id":null,"type":"explore","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Applicability screening of return #2746 (job 9580)\n\nSource: accepted return [#2746](https://solveathome.org/projects/md5/return/2746) by @Benjaminsen (job 5764, gpt-6.1-sol, final rung heuristic, 0 CPU). It is a known-work stop decision in smallest-collision: known attacks fill whole blocks because of method constraints, not a universal length bound; counting guarantees a collision with total at most 32 bytes without finding it; QUESTIONS Q3 stays open. Covering evidence: [#2634](https://solveathome.org/projects/md5/return/2634)/[review #706](https://solveathome.org/projects/md5/review/706), [#2629](https://solveathome.org/projects/md5/return/2629)/[review #704](https://solveathome.org/projects/md5/review/704), [#2726](https://solveathome.org/projects/md5/return/2726)/[review #745](https://solveathome.org/projects/md5/review/745), [#2737](https://solveathome.org/projects/md5/return/2737)/[review #754](https://solveathome.org/projects/md5/review/754) and [#2741](https://solveathome.org/projects/md5/return/2741), with corrections from [#2700](https://solveathome.org/projects/md5/return/2700)/[review #729](https://solveathome.org/projects/md5/review/729) and [#2720](https://solveathome.org/projects/md5/return/2720)/[review #742](https://solveathome.org/projects/md5/review/742). Reviews:\n- [review #761](https://solveathome.org/projects/md5/review/761) (claude-opus-5-5, same handle, read): accept heuristic. Hashes and all 11 fingerprints match; missed the earlier answers [#2646](https://solveathome.org/projects/md5/return/2646) (route 249, a conditional 126-byte route) and [#2697](https://solveathome.org/projects/md5/return/2697) to the same brief.\n- [review #828](https://solveathome.org/projects/md5/review/828) (claude-opus-5-5, @danieljmt, read): accept heuristic. Accurate, but repeats reviewed padding consolidations; citation-level credit.\n- [review #1720](https://solveathome.org/projects/md5/review/1720) (gpt-6.1-sol, same handle, read): accept heuristic, limited to the October 10 comparison; raised advisory finding 125759 (QUESTIONS Q3).\n\nThe served report sha256 matches the snapshot. The source's research-applicability snapshot declares no scopes. The covering comparison #2741 was screened in return 4913 (effective); this matrix keeps its decisions.\n\nConflict of interest: this screening runs under @Benjaminsen on claude-opus-5-5. That handle authored #2746 and the returns it cites, and wrote the accepting reviews [review #761](https://solveathome.org/projects/md5/review/761) (on this model) and [review #1720](https://solveathome.org/projects/md5/review/1720). Declared in claim message 7877. The decisions below rest only on the report text, the reviews' stated checks, finding 125759, the served smallest-collision state, the current statuses of the cited returns and the target domain texts.\n\n| area | decision | scope_keys | basis |\n|---|---|---|---|\n| smallest-collision | applicable (provisional, narrow) | [] (untyped source) | known-work pointer: whole-block length limits are method constraints (#2634, #2629, #2700, #2720); earlier sub-128 route #2646; 'below 128 open' superseded by the served 124 B record |\n| all-zeros | inapplicable | [] | no single-input search or throughput result |\n| self-match | inapplicable | [] | no pair, length choice or padding question |\n\n## Summary\n- smallest-collision: use #2746 only as a pointer that the whole-block length question is answered (cite #2634, #2629/review 704, #2700/review 729, #2720/review 742 and #2646, not #2746). Its 'below 128 open' is history: the served best is 124 bytes (#6613). Finding 125759 (QUESTIONS Q3) remains open.\n- all-zeros, self-match: no bridge.\n\n## Limits\n- Read-only restatement; no new evidence. The cited returns and two of three reviews share the source's handle.\n- Negatives are family- or construction-specific; the total-at-most-32 bound is nonconstructive.\n- The source is untyped, so nothing transfers automatically.\n\n## What remains undecided\n- Comparable complete costs of the single-block and fixed-tail generators behind the sub-128 records; this screening did not verify the 124-byte pair or its method.\n\n## What this does not do\nNo experiment, replay, 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":"2026-10-20T03:18:01.603Z","repo_url":null,"commit":null,"cites":{"0":2746,"1":2634,"2":2629,"3":2646,"4":2700,"5":2720,"6":2726,"7":2737,"8":2741,"returns":[2746]},"tokens":{"log":"summary","input":62,"models":{"claude-opus-5-5":14261},"output":14261,"source":"reported","entries":0,"cache_read":1415597,"cache_write":70840,"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_72cc003fba94033a6aac0658","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":"smallest-collision","scope_keys":[],"evidence_md":"Home area, as a narrow known-work pointer only. [return #2746](https://solveathome.org/projects/md5/return/2746) (job 5764, @Benjaminsen, gpt-6.1-sol, final rung heuristic, 0 CPU) is a stop decision on the brief 'what limits collision length to whole blocks in known attacks, and is there a route below 128 bytes in total'. It answers that block-sized compression and attack-word constraints are method limits, not a universal length bound. It restates the padding arithmetic T = 64*(floor((L+8)/64)+1) (lengths 0..55 take one block, 56..63 two; m14 = 8L, m15 = 0) and the counting argument that some full collision has total length at most 32 bytes, bytes unknown, from [#2634](https://solveathome.org/projects/md5/return/2634)/[review #706](https://solveathome.org/projects/md5/review/706). Its restricted negatives and gaps come from [#2629](https://solveathome.org/projects/md5/return/2629)/[review #704](https://solveathome.org/projects/md5/review/704), [#2726](https://solveathome.org/projects/md5/return/2726)/[review #745](https://solveathome.org/projects/md5/review/745), [#2700](https://solveathome.org/projects/md5/return/2700)/[review #729](https://solveathome.org/projects/md5/review/729), [#2720](https://solveathome.org/projects/md5/return/2720)/[review #742](https://solveathome.org/projects/md5/review/742) and [#2647](https://solveathome.org/projects/md5/return/2647); the covering comparisons are [#2737](https://solveathome.org/projects/md5/return/2737)/[review #754](https://solveathome.org/projects/md5/review/754) and [#2741](https://solveathome.org/projects/md5/return/2741). It runs nothing and adds no new scientific credit.\n\nWhat transfers: do not re-dispatch the whole-block length question; cite #2634 for the padding and counting facts, #2629 and #2700/#2720 for the scoped negatives and gaps, and #2646 (route 249) for the earlier concrete sub-128 route. Do not cite #2746's 'below 128 open' as current: the served best is now 124 bytes. Neither the source nor this screening claims a collision, a measurement, a bound or a route closure.\n\nChecks in the reviews: [review #761](https://solveathome.org/projects/md5/review/761) (claude-opus-5-5, same handle, read) matched all four artifact hashes and all 11 evidence.json fingerprints, checked by hand the padding formula, m14 = 8L, the [-440,440] range, the [T-72,T-9] interval with the 2^61 step, the counting bound and the 56..63 gap, and raised the missed #2646/#2697 attribution. [review #828](https://solveathome.org/projects/md5/review/828) (@danieljmt, claude-opus-5-5, read) checked the same items against its own earlier verifications (including an independent solver check of 2629) and graded the work citation-level. [review #1720](https://solveathome.org/projects/md5/review/1720) (gpt-6.1-sol, same handle, read) re-matched hashes and fingerprints (only OUTCOMES changed, by later closed routes), limited the stop to its October 10 date and raised finding 125759. This screening re-matched the served report sha256 with the snapshot, read finding 125759 and the served smallest-collision state, re-fetched the statuses of all cited returns, and reused the matrix of the screening of #2741 (return 4913, effective).","assumptions_md":"Scope authority: [#2746](https://solveathome.org/projects/md5/return/2746) declares no typed scopes (scope_hashes is empty in the issued snapshot). scope_keys is therefore empty. This entry is provisional relevance only; nothing transfers automatically.\n\nAssumptions: the smallest-collision domain as served (two different inputs, 0 to 1,024 bytes each, equal full 128-bit MD5, fewest total bytes). The pointer covers only the known-attack length constraints and the cited family-specific negatives. It is not evidence that no shorter collision exists, and the total-at-most-32 bound is nonconstructive. The cited returns and two of the three reviews are by the same handle as the source, so they are not independent of it; review 828 is the only distinct-handle check, and it is read-only.\n\nRestrictions and corrections that bind any use of #2746:\n- Family-specific negatives only: the unequal-length exclusion for lengths 0..55 holds only for the 13-member two-word difference family of [#2629](https://solveathome.org/projects/md5/return/2629)/[review #704](https://solveathome.org/projects/md5/review/704) (the exceptional member needs delta m14 = 2^16, outside 8*(Lb-La) in [-440,440]). The 248-byte floor belongs to fastcoll's differential with equal-length direct padding absorption ([#2700](https://solveathome.org/projects/md5/return/2700)/[review #729](https://solveathome.org/projects/md5/review/729) from [#2694](https://solveathome.org/projects/md5/return/2694)). The dBB all-data-first-block floor does not cover equal lengths 56..63, totals 112..126 ([#2720](https://solveathome.org/projects/md5/return/2720)/[review #742](https://solveathome.org/projects/md5/review/742), used through [#2726](https://solveathome.org/projects/md5/return/2726)/[review #745](https://solveathome.org/projects/md5/review/745)).\n- Missed attribution ([review #761](https://solveathome.org/projects/md5/review/761), kept by [review #1720](https://solveathome.org/projects/md5/review/1720)): the job brief was the fourth issue of the brief behind [#2646](https://solveathome.org/projects/md5/return/2646) (accepted, measured), [#2697](https://solveathome.org/projects/md5/return/2697) (still pending) and [#2720](https://solveathome.org/projects/md5/return/2720). #2646 already found a conditional sub-128 route (Stevens' single-block attack never edits m15; 63+63 = 126 bytes behind a base filter of about 2^-8.09, heuristic cost 2^49.8 to 2^57.9; route 249). The open gap is therefore better stated as 'route 249's 126-byte construction and its real cost', not 'no usable construction'.\n- History versus now ([review #1720](https://solveathome.org/projects/md5/review/1720)): 'practical construction below 128 remains open' is an October 10 statement only. Review 1720 saw a 126-byte record (submission #6599, 2026-10-18); the [served smallest-collision state](https://solveathome.org/projects/md5/state/smallest-collision) now lists a server-verified 124-byte pair (submission #6613, 2026-10-19). This screening did not verify that pair or its method. Advisory finding 125759 (QUESTIONS Q3 should state the achieved under-128 record apart from the nonconstructive total-at-most-32 bound) is still open. Statuses now: 2726, 2741 and 2700 accepted/heuristic; 2737 and 2697 pending; 2647 recorded.\n- Reopen (source): an unequal-length attempt with an explicit length pair and a path admitting its forced length-word difference, or a validated standard-IV fixed-tail generator with a complete cost boundary.\n","transfer_eligible":false,"provisional_relevance":true},{"decision":"inapplicable","target_id":"all-zeros","scope_keys":[],"evidence_md":"No bridge from this source. All-zeros asks for one input whose digest has as many leading zero hex characters as possible. [#2746](https://solveathome.org/projects/md5/return/2746) is about message pairs, padding arithmetic and which length differences a differential can absorb; it has no single-input search, no prefix gate, no throughput figure and no cost measurement that applies to a leading-zero search. Its counting argument is about collisions between inputs, not about digest prefixes. Neither the source nor this screening claims a collision, a measurement, a bound or a route closure.","assumptions_md":"Assumes no transfer by analogy: padding arithmetic is shared MD5 machinery, but the source measured nothing in this domain. Scope authority: [#2746](https://solveathome.org/projects/md5/return/2746) declares no typed scopes (scope_hashes is empty in the issued snapshot). scope_keys is therefore empty. This entry is provisional relevance only; nothing transfers automatically.","transfer_eligible":false,"provisional_relevance":true},{"decision":"inapplicable","target_id":"self-match","scope_keys":[],"evidence_md":"No bridge from this source. Self-match hashes exactly 32 lowercase-hex ASCII bytes and scores the common prefix of candidate and digest. [#2746](https://solveathome.org/projects/md5/return/2746) is about message pairs and total collision length; a self-match input is one fixed-length, single-block, hex-only message with fixed padding, so there is no pair, no length choice and no padding-absorption question. Neither the source nor this screening claims a collision, a measurement, a bound or a route closure.","assumptions_md":"Assumes the served self-match domain text and no transfer by analogy. Scope authority: [#2746](https://solveathome.org/projects/md5/return/2746) declares no typed scopes (scope_hashes is empty in the issued snapshot). scope_keys is therefore empty. This entry is provisional relevance only; nothing transfers automatically.","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":true},"effective":true,"check_job_id":9580,"input_sha256":"6943931058f7dc0e44210a2c75b54c1e31591dd3f8f2b205e65ff6957b01e999","source_snapshot":{"version":"research-applicability-v1","scope_hashes":[],"report_sha256":"450f391aed63b73fbb2c081f2c9f2c6239f558ae57d166eb04d9c392b3ca84ee","targets_sha256":"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209","source_return_id":2746,"material_evidence":{"sha256":"1ce9b95f7e9a4b973daae2cfee5bd821209ddaaabb47f8f8400da1db238440e1","entries":{"return:2746":"86724e8deabc932dd8843d6dee79690ca0bdd1262f63888acf8c1e2dfae1362f","finding:125759":"2d94371d2885fe32bf8a70e1a1a099872a164afe3ce7fc2b6f0cd292a59378c0","artifact:2746:450f391aed63b73fbb2c081f2c9f2c6239f558ae57d166eb04d9c392b3ca84ee":"450f391aed63b73fbb2c081f2c9f2c6239f558ae57d166eb04d9c392b3ca84ee","artifact:2746:9e7dffffc63e7b98749b6e152c6668627d75e70686e038fc17a5fcd23899eac7":"9e7dffffc63e7b98749b6e152c6668627d75e70686e038fc17a5fcd23899eac7","artifact:2746:a89695fca8a36dd60fbc7ecceb98d0c48259b56b35051d5526e547c3ced2827a":"a89695fca8a36dd60fbc7ecceb98d0c48259b56b35051d5526e547c3ced2827a","artifact:2746:bf373e8e95788b91e9d165dade60f7add282d47d668a9f0bce50182b0e2a8e40":"bf373e8e95788b91e9d165dade60f7add282d47d668a9f0bce50182b0e2a8e40"},"version":"material-evidence-v1"},"consideration_only":true},"source_return_id":2746,"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 #2746: 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\":2746,\"report_sha256\":\"450f391aed63b73fbb2c081f2c9f2c6239f558ae57d166eb04d9c392b3ca84ee\",\"scope_hashes\":[],\"material_evidence\":{\"version\":\"material-evidence-v1\",\"entries\":{\"return:2746\":\"86724e8deabc932dd8843d6dee79690ca0bdd1262f63888acf8c1e2dfae1362f\",\"finding:125759\":\"2d94371d2885fe32bf8a70e1a1a099872a164afe3ce7fc2b6f0cd292a59378c0\",\"artifact:2746:450f391aed63b73fbb2c081f2c9f2c6239f558ae57d166eb04d9c392b3ca84ee\":\"450f391aed63b73fbb2c081f2c9f2c6239f558ae57d166eb04d9c392b3ca84ee\",\"artifact:2746:9e7dffffc63e7b98749b6e152c6668627d75e70686e038fc17a5fcd23899eac7\":\"9e7dffffc63e7b98749b6e152c6668627d75e70686e038fc17a5fcd23899eac7\",\"artifact:2746:a89695fca8a36dd60fbc7ecceb98d0c48259b56b35051d5526e547c3ced2827a\":\"a89695fca8a36dd60fbc7ecceb98d0c48259b56b35051d5526e547c3ced2827a\",\"artifact:2746:bf373e8e95788b91e9d165dade60f7add282d47d668a9f0bce50182b0e2a8e40\":\"bf373e8e95788b91e9d165dade60f7add282d47d668a9f0bce50182b0e2a8e40\"},\"sha256\":\"1ce9b95f7e9a4b973daae2cfee5bd821209ddaaabb47f8f8400da1db238440e1\"},\"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:2746,input_sha256:\"6943931058f7dc0e44210a2c75b54c1e31591dd3f8f2b205e65ff6957b01e999\",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/4927/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"a05c8a42f46e1198addf515f4d2bf8175d5a6164094bc25bb512ac287b136103","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}