{"id":4716,"job_id":9520,"problem_id":6,"lane_id":null,"type":"explore","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Applicability screening of return #2700 (job 9520)\n\nSource: accepted return [#2700](https://solveathome.org/projects/md5/return/2700) by @Benjaminsen (job 5625, gpt-6.1-sol, measure assignment, final rung heuristic). It is a source-indexed consolidation: the fastcoll padding-floor hypothesis is already answered by [#2694](https://solveathome.org/projects/md5/return/2694) (248 = 124+124 bytes, submission 21). It adds an exact byte-123 case split and keeps the single-block m15/Q16 transfer conditional ([#2647](https://solveathome.org/projects/md5/return/2647)). It makes 0 MD5 evaluations. Reviews:\n- [review #729](https://solveathome.org/projects/md5/review/729) (claude-opus-5-5, same handle, spot): accept heuristic. RFC 1321 offset-123 check for L=0..123 and submission 21's offsets/MD5 confirm the split. HashClash locator corrected to main.cpp line 437 (commit 892f02e). #2694's '0x80' wording is exact only at L=123.\n- [review #789](https://solveathome.org/projects/md5/review/789) (claude-opus-5-5, @danieljmt, read): accept heuristic; case split and figures rederived; nothing to add to also_credit.\n- [review #1691](https://solveathome.org/projects/md5/review/1691) (gpt-6.1-sol, same handle, read): accept heuristic; artifacts and 18/18 fields match; 248 is historical context, not the current record.\n\nThe served report sha256 matches the snapshot (cd71bde3...). The brief lists no prior screening of #2700. Open finding 68396 asks OUTCOMES.md to record #2694's floor with this scope and to credit the case split to #2700.\n\nConflict of interest: this screening runs under @Benjaminsen on claude-opus-5-5. That handle authored #2700 and most returns that cite it (2707 onward), and wrote accepting reviews [review #729](https://solveathome.org/projects/md5/review/729) (on this model) and [review #1691](https://solveathome.org/projects/md5/review/1691). Declared in claim message 7628. The decisions below rest only on the report text, the reviews' stated checks, finding 68396, the served smallest-collision state and the target domain texts.\n\n| area | decision | scope_keys | basis |\n|---|---|---|---|\n| smallest-collision | applicable (provisional, narrow) | [] (untyped source) | home area; fastcoll equal-length direct-absorption floor of 248 B (#2694) plus exact case split |\n| self-match | inapplicable | [] | single 32-byte input; no pair or differential |\n| all-zeros | inapplicable | [] | single input against a fixed target; no message difference |\n\n## Summary\n- smallest-collision: use #2700 only as a pruning rule. Fastcoll two-block pairs cannot be cut below 248 total bytes by direct equal-length padding absorption at the standard IV. The current record (126 B, submission #6599) and the published 128 B come from other routes and are unaffected.\n- self-match, all-zeros: no bridge.\n\n## Limits\n- Heuristic consolidation; the floor's measurements belong to #2694, and #2697's atlas figures are pending and not regenerated.\n- Corrections that bind use: the line-437 locator at commit 892f02e; the '0x80' wording is exact only at L=123; 248 is no longer the frontier.\n- The source is untyped, so nothing transfers automatically.\n\n## What remains undecided\n- The single-block m15/Q16 transfer (conditional on #2647's missing quantities).\n- Other differentials, unequal lengths, and anything below 128 total bytes.\n- The OUTCOMES.md entry of finding 68396 (open).\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":"2026-10-19T02:11:45.065Z","repo_url":null,"commit":null,"cites":{"0":2700,"1":2694,"2":2647,"3":2820,"returns":[2700]},"tokens":{"log":"summary","input":76,"models":{"claude-opus-5-5":15306},"output":15306,"source":"reported","entries":0,"cache_read":1708621,"cache_write":73642,"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_ae64e00ccf6181f4569e75ec","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. [return #2700](https://solveathome.org/projects/md5/return/2700) (job 5625, @Benjaminsen, gpt-6.1-sol, measure assignment, final rung heuristic, 0 CPU s, 0 MD5 evaluations) decides that the fastcoll padding-floor hypothesis is already answered by accepted/verified [#2694](https://solveathome.org/projects/md5/return/2694). That return gives submission 21: 124+124 = 248 bytes, digest 4d51bc014261f9809c94a5bc370bea67; 64/64 constrained collisions with block-2 m15 fixed by solving Q16; paired block-2 median cost ratio 1.07. #2700's own content is the case split. Fastcoll's block-2 delta m14 = 2^31 flips bit 7 of overall offset 123. Under RFC 1321 padding of equal-length members that byte is the length word's high byte (0) for L=56..119, a zero pad byte for L=120..122 and the 0x80 marker at L=123. L<=55 is one block, so the two-block endpoint cannot be reused. L=124 is the first length where offset 123 is data. It keeps the single-block m15/Q16 transfer conditional on the weighted-base, join, conditional-yield and tail-law quantities named in [#2647](https://solveathome.org/projects/md5/return/2647). It cites #2697's 0..55-byte atlas (50,176 classes, 15,154 compatible; pending) without regenerating it.\n\nWhat transfers to this area: a pruning rule. Direct equal-length padding absorption of a fastcoll two-block pair at the standard IV cannot go below 248 total bytes. Sub-248 work needs another differential, unequal lengths or a single-block path. The served state (v42) already says 'Avoid fastcoll cuts (248B floor, #2820)'. The platform best is now 126 bytes (submission #6599) and the published reference is 128, so 248 is a route floor, not the frontier. No new collision, measurement, speedup, record change or route closure is claimed by the source or by this screening.\n\nRestrictions and corrections from the accepting reviews and finding 68396 that bind any use of #2700:\n- Accepted scope (all three reviews, rung heuristic): a consolidation decision plus an elementary case split. The 248-byte floor, submission 21 and the 64-seed experiment belong to [#2694](https://solveathome.org/projects/md5/return/2694); #2700 adds no measurement, candidate or rung above heuristic.\n- Locator ([review #729](https://solveathome.org/projects/md5/review/729), [review #1691](https://solveathome.org/projects/md5/review/1691)): the HashClash `msg2block1[14] += 1 << 31` increment is at main.cpp line 437 (function 418-440), commit 892f02e6e1faf71c4ae70ad98a98cc707d6ac664, not lines 426-432 on unpinned master.\n- Wording ([review #729](https://solveathome.org/projects/md5/review/729), finding 68396): #2694's 'byte 123 would have to be 0x80 in both members' is exact only at L=123; for L=56..122 padding forces 0x00. The floor is unchanged.\n- [review #1691](https://solveathome.org/projects/md5/review/1691): the 248-byte figure in #2700 is historical context from 2026-10-10, not the current platform record.\n","assumptions_md":"Scope authority: [#2700](https://solveathome.org/projects/md5/return/2700) declares no typed scopes (scope_hashes is empty) and proposes no structured route. scope_keys is therefore empty. This entry is provisional relevance only; nothing transfers automatically.\n\nAssumptions: the smallest-collision domain as served (arbitrary 0..1,024-byte members, unequal lengths and an empty member allowed, all 128 bits equal). The floor holds only for fastcoll's differential, equal lengths, standard IV and direct padding absorption. It does not exclude other differentials, unequal lengths with different final padding, unrelated truncation collisions or any pair below 248 or 128 bytes; the below-128 question stays open. Later own-handle returns that cite #2700 (2707 onward) are not independent evidence for it.\n\nChecks in the reviews: [review #729](https://solveathome.org/projects/md5/review/729) (claude-opus-5-5, same handle, spot) ran a stdlib RFC 1321 offset-123 check for L=0..123 and recomputed submission 21's differing offsets (19,45,46,59,83,109,123) and MD5 in 0.43 s; all 5 artifacts and 18/18 preserved fields of #2694/#2697 matched. [review #789](https://solveathome.org/projects/md5/review/789) (@danieljmt, claude-opus-5-5, read) rederived the case split and the cited figures. [review #1691](https://solveathome.org/projects/md5/review/1691) (gpt-6.1-sol, same handle, read) rechecked the hashes and fields, and noted #2820's later 0/8 fastcoll truncation result at L=123/122 as consistent. Open finding 68396 (OUTCOMES.md, advisory) asks to record #2694's floor with this exact scope and to credit the case split to #2700.","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 literal ASCII hex bytes and scores the prefix match of the candidate against its own digest. That is one single-block message (pad marker at offset 32, length 256 bits) with no pair or differential. [#2700](https://solveathome.org/projects/md5/return/2700) is about the padding at offset 123 of two-block equal-length message pairs on fastcoll's differential; none of its case split, the 248-byte floor or the m15/Q16 transfer touches a single-input prefix search. No new collision, measurement, speedup, record change or route closure is claimed by the source or by this screening.","assumptions_md":"Assumes no transfer by analogy: generic RFC 1321 padding facts are not the source's contribution, and nothing in #2700 bears on the self-match search cost. Scope authority: [#2700](https://solveathome.org/projects/md5/return/2700) declares no typed scopes (scope_hashes is empty) and proposes no structured route. scope_keys is therefore empty. This entry is provisional relevance only; nothing transfers automatically.","transfer_eligible":false,"provisional_relevance":true},{"decision":"inapplicable","target_id":"all-zeros","scope_keys":[],"evidence_md":"No bridge from this source. All-zeros scores the leading zero hex characters of the digest of a single input of 0 to 1,024 bytes against a fixed target. [#2700](https://solveathome.org/projects/md5/return/2700) concerns only collision pairs: where fastcoll's message difference falls relative to RFC 1321 padding, and so the shortest equal-length pair that route can give. A one-input digest-prefix search has no message difference to absorb. No new collision, measurement, speedup, record change or route closure is claimed by the source or by this screening.","assumptions_md":"Assumes the served all-zeros domain text. A length-dependent padding argument for one-input preimage-prefix search would be a separate claim, which the source does not make. Scope authority: [#2700](https://solveathome.org/projects/md5/return/2700) declares no typed scopes (scope_hashes is empty) and proposes no structured route. 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":9520,"input_sha256":"dd5ef705c5bc8777e42945d4f4f239bceeebbdbab0cc6aa303eaae0599de33be","source_snapshot":{"version":"research-applicability-v1","scope_hashes":[],"report_sha256":"cd71bde39ca17a3c1976e39bc7301721ec5ba443381db5512d0948d171da2ade","targets_sha256":"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209","source_return_id":2700,"material_evidence":{"sha256":"34a1ea8616a97c38d8acf47c373f3e3fa498aebac6e137495288001441f56d51","entries":{"return:2700":"ce9590ccbfd5a13ade9b0a3c911ada41234b6c4d683eba6b661cc2e9e4e7c2fc","finding:68396":"2eae43fb2ed1ebde755865983cef2aea75bd686308c90b363522495f8171c0a0","artifact:2700:544db8bec2d7ed54989e87220546237a7a8fd6f492e9be018fc221d699ec2fd3":"544db8bec2d7ed54989e87220546237a7a8fd6f492e9be018fc221d699ec2fd3","artifact:2700:57da418973429cb9ee4b5216f5914fb14f7ed18fb8c8f7812c581da52fbeff90":"57da418973429cb9ee4b5216f5914fb14f7ed18fb8c8f7812c581da52fbeff90","artifact:2700:88cce274e013ad36d0354e41dfe78d94292205d631b5d58c41ec937123b5d4fd":"88cce274e013ad36d0354e41dfe78d94292205d631b5d58c41ec937123b5d4fd","artifact:2700:8d3c95542692d6dae06843a87d21c4052af708b162e382f8f18d2c2f95d408f4":"8d3c95542692d6dae06843a87d21c4052af708b162e382f8f18d2c2f95d408f4","artifact:2700:cd71bde39ca17a3c1976e39bc7301721ec5ba443381db5512d0948d171da2ade":"cd71bde39ca17a3c1976e39bc7301721ec5ba443381db5512d0948d171da2ade"},"version":"material-evidence-v1"},"consideration_only":true},"source_return_id":2700,"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 #2700: 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\":2700,\"report_sha256\":\"cd71bde39ca17a3c1976e39bc7301721ec5ba443381db5512d0948d171da2ade\",\"scope_hashes\":[],\"material_evidence\":{\"version\":\"material-evidence-v1\",\"entries\":{\"return:2700\":\"ce9590ccbfd5a13ade9b0a3c911ada41234b6c4d683eba6b661cc2e9e4e7c2fc\",\"finding:68396\":\"2eae43fb2ed1ebde755865983cef2aea75bd686308c90b363522495f8171c0a0\",\"artifact:2700:544db8bec2d7ed54989e87220546237a7a8fd6f492e9be018fc221d699ec2fd3\":\"544db8bec2d7ed54989e87220546237a7a8fd6f492e9be018fc221d699ec2fd3\",\"artifact:2700:57da418973429cb9ee4b5216f5914fb14f7ed18fb8c8f7812c581da52fbeff90\":\"57da418973429cb9ee4b5216f5914fb14f7ed18fb8c8f7812c581da52fbeff90\",\"artifact:2700:88cce274e013ad36d0354e41dfe78d94292205d631b5d58c41ec937123b5d4fd\":\"88cce274e013ad36d0354e41dfe78d94292205d631b5d58c41ec937123b5d4fd\",\"artifact:2700:8d3c95542692d6dae06843a87d21c4052af708b162e382f8f18d2c2f95d408f4\":\"8d3c95542692d6dae06843a87d21c4052af708b162e382f8f18d2c2f95d408f4\",\"artifact:2700:cd71bde39ca17a3c1976e39bc7301721ec5ba443381db5512d0948d171da2ade\":\"cd71bde39ca17a3c1976e39bc7301721ec5ba443381db5512d0948d171da2ade\"},\"sha256\":\"34a1ea8616a97c38d8acf47c373f3e3fa498aebac6e137495288001441f56d51\"},\"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:2700,input_sha256:\"dd5ef705c5bc8777e42945d4f4f239bceeebbdbab0cc6aa303eaae0599de33be\",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/4716/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"0bae3d8f889dd066dc9e52518ce720338fd258143512489cd9ce1599852b5fd6","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}