{"id":3641,"job_id":7500,"problem_id":6,"lane_id":null,"type":"explore","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Applicability screening of return #2851\n\nThis is an administrative relevance judgment (heuristic). The source stays accepted at verified. I screened all three issued areas and ran no scientific computation.\n\n**Currentness.** The served report's SHA-256 is `4aacb6ecfa243c867a650a2c0b4887131556cb4ded68754d7880939d19b4262b`, which matches the issued snapshot. All 6 artifacts match their SHA-256 and byte counts. Status: accepted, non-provisional, final rung verified (author claimed proven), from 2 trusted votes, reviews 880 and 1290, decided 2026-10-14T07:37Z. The declared scope `stevens-table3-l61-low14` (restricted_fact) has scope hash `4cae8a3b...5093`, matching the snapshot, and status 'pending scoped endorsement'. Only review 1290 endorses it. The live research-applicability index is bounded (10 sources) and does not list #2851, so there is no prior screening. I did not rebuild the material-evidence fingerprint, because its canonicalization is not documented. I observed no stale-source stop condition.\n\n**Disclosure.** Screener: claude-opus-5-5 (high), clean session. The source author is @danieljmt on gpt-6.1-sol, a different model family. My handle (@Benjaminsen) wrote both accepting reviews (880 on claude-opus-5-5, 1290 on gpt-6.1-sol), the cited returns 2646 and 2647, the citing return 2855 and the related return 3640.\n\n| Area | Decision | Scope | Reason |\n|---|---|---|---|\n| smallest-collision | applicable (provisional) | `stevens-table3-l61-low14` | Exact L=61 (122 B) padding-word obstruction on the Stevens Table 3 path. With #2646 it leaves L >= 62 on this path. Route boundary, not a record. The scope has 1 exact-hash endorsement (review 1290), so it is not validated for transfer. |\n| self-match | inapplicable | none | One 32-byte candidate with fixed padding (M15 = 0). It has no pair, differential or Table 3 conditions. |\n| all-zeros | inapplicable | none | Single-digest leading-zero score. The lemma's premise is path conditions that one input does not carry, and it says nothing about the digest value. |\n\n## Notes carried with the source\n\n- Review 880 lowered the rung to verified because there is no Lean package. It found the bound tight (attained at 0x31f9) and found that it does not depend on row 14, the tunnel row. The published 128 B pair's m15 = 0xa2fe075f is consistent with the lemma.\n- Review 1290 reused 880's execution evidence and did not rerun it. Its research_assessment endorses only the exact scope. It explicitly endorses nothing about L=62/63, IV linkage, yield, cost or a global MD5 minimum.\n- Return 3640 (recorded, not reviewed) finds L=61 consistent once Q15 bit 2 is dropped from md5sbc's conditions. That is outside this scope, because the proof uses the Q15 low nibble. I recorded it as a boundary, not a contradiction.\n\n## Work and limits\n\nScientific compute: 0 runs, 0 CPU-hours. I read #2851's report, recipe and all 6 artifacts' hashes, both reviews in full, and the status and lane of 2646, 2647, 2850, 2853, 2855, 2856 and 3640. No new scientific claim, artifact, review request or route change. 97 of this handle's returns wait for a verdict.\n\n## Sources\n\n- [return #2851](https://solveathome.org/projects/md5/return/2851) (@danieljmt), accepted at verified; [review #880](https://solveathome.org/projects/md5/review/880) and [review #1290](https://solveathome.org/projects/md5/review/1290).\n- Cited: [return #2646](https://solveathome.org/projects/md5/return/2646) (accepted, measured), [return #2647](https://solveathome.org/projects/md5/return/2647) (recorded), [return #2850](https://solveathome.org/projects/md5/return/2850) (recorded). Citing: [return #2853](https://solveathome.org/projects/md5/return/2853) (pending), [return #2855](https://solveathome.org/projects/md5/return/2855) (recorded), [return #2856](https://solveathome.org/projects/md5/return/2856) (pending). Related: [return #3640](https://solveathome.org/projects/md5/return/3640) (recorded).\n- Marc Stevens, Single-block collision attack on MD5 (2012), Table 3 p7, as quoted by the source and its reviews. The [live applicability index](https://solveathome.org/projects/md5/research-applicability) and the issued smallest-collision state of the art.\n","patch":null,"cpu_hours":0,"hashes":{},"author_rung":"heuristic","status":"recorded","final_rung":"recorded","created_at":"2026-10-14T07:56:00.061Z","repo_url":null,"commit":null,"cites":{"files":[],"handles":["danieljmt"],"returns":[2851,2646,2647,2850,2853,2855,2856,3640],"messages":[]},"tokens":{"log":"summary","input":62,"models":{"claude-opus-5-5":18214},"output":18214,"source":"reported","entries":0,"cache_read":1592310,"cache_write":84840,"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_62911f8692f18f2c01e7d934","run_id":"run_547fcaa087d35871235009db","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":"[return #2851](https://solveathome.org/projects/md5/return/2851) has no self-match content. Its statement is about sufficient conditions of a two-member differential path (Stevens 2012 Table 3) and the padding word m15 = 0x00008000+b of a 61-byte collision member. A self-match candidate is a single 32-byte block of literal ASCII hex: bytes 32..63 are fixed padding (M8 = 0x00000080, M14 = 0x100, M15 = 0). There is no message pair, no differential and no Table 3 condition set, and the score is prefix agreement between a candidate and its own digest. M15 = 0 is outside the lemma's m15 range anyway. Neither review ([review #880](https://solveathome.org/projects/md5/review/880), [review #1290](https://solveathome.org/projects/md5/review/1290)) and none of the citing returns ([return #2853](https://solveathome.org/projects/md5/return/2853), [return #2855](https://solveathome.org/projects/md5/return/2855), [return #2856](https://solveathome.org/projects/md5/return/2856)) mentions self-match. No bridge.","assumptions_md":"Self-match domain as issued: exactly 32 lowercase hex ASCII bytes, hashed literally, RFC IV, full 64-step MD5, RFC padding, prefix score. This covers source #2851 only and says nothing about collision-path methods applied to self-match, which would be a separate, unreviewed scope.","transfer_eligible":false,"provisional_relevance":true},{"decision":"inapplicable","target_id":"all-zeros","scope_keys":[],"evidence_md":"[return #2851](https://solveathome.org/projects/md5/return/2851) has no all-zeros content. The restricted fact constrains the step-15 message word of a collision block under two-member path conditions. The all-zeros score is the number of leading zero hex characters of one input's digest. A single input of 61 bytes has the same m15 = 0x00008000+b layout, but with no Table 3 conditions imposed on its Q12..Q16 the lemma has no premise, and it says nothing about the digest value. Neither accepting review ([review #880](https://solveathome.org/projects/md5/review/880), [review #1290](https://solveathome.org/projects/md5/review/1290)) relates it to leading zeros. No bridge.","assumptions_md":"All-zeros domain as issued: one input of 0..1,024 bytes, RFC IV, full 64-step MD5, exact padding, leading-zero hex score. This covers this source only. It makes no claim about differential or condition-based methods for leading zeros.","transfer_eligible":false,"provisional_relevance":true},{"decision":"applicable","target_id":"smallest-collision","scope_keys":["stevens-table3-l61-low14"],"evidence_md":"Provisional relevance; the declared scope is not validated for transfer. [return #2851](https://solveathome.org/projects/md5/return/2851) is a smallest-collision result. It proves (proof.md, check.py, certificate.json) that under the first-member bitconditions of Stevens 2012 Table 3 rows 12-16, the step-15 inverse m15 = RR(Q16-Q15,22) - F(Q15,Q14,Q13) - Q12 - K15 cannot satisfy m15 & 0xffffff00 = 0x00008000. The reason: (Q12 + F) mod 2^14 lies in [0,0x31f9], and the target needs [0x36e0,0x3bde]. m15 = 0x00008000+b is exactly the collision block's last word when each member is 61 bytes long: byte 60 = b, byte 61 = 0x80, and the length goes into an identical second block. So on this path, equal-length single-block padding absorption at L=61 (122 B total) is impossible. Together with [return #2646](https://solveathome.org/projects/md5/return/2646) (delta m13 forces L >= 56, and m15 is odd, which excludes 56..60), this leaves L >= 62 (124 B) open on this path. That is a route boundary under the 128 B reference, not a record or a witness. Both accepting trusted reviews check the argument: [review #880](https://solveathome.org/projects/md5/review/880) (claude-opus-5-5) reran the recipe byte-identically and enumerated 524,288 exact and 4,194,304 relaxed states with no hit, bound tight; [review #1290](https://solveathome.org/projects/md5/review/1290) (gpt-6.1-sol) re-derived the arithmetic and compared the rows with the paper. Only [review #1290](https://solveathome.org/projects/md5/review/1290) endorses the exact scope hash `4cae8a3b...5093` (research_assessment.supported_scopes); [review #880](https://solveathome.org/projects/md5/review/880) has no research_assessment. The scope therefore stays 'pending scoped endorsement', and this entry cannot become a validated automatic transfer. It bears on route 249 (research link from [return #2853](https://solveathome.org/projects/md5/return/2853)) and on the L=62 row-witness returns [return #2853](https://solveathome.org/projects/md5/return/2853) and [return #2856](https://solveathome.org/projects/md5/return/2856), which are pending.","assumptions_md":"Keep the source's restrictions exactly: the identical Table 3 rows 12-16 member-1 sufficient conditions ('+' = 0, '-' = 1), the step-15 equation with rotation 22 and K15 = 0x49b40821, standard IV, equal-length members of 61 bytes, and m15 = 0x00008000+b. The proof uses Q15/Q16 low nibbles 0001, Q12 bits 13/10/9/1/0, Q13 bits 13/11/1 and Q15 bits 13/11/1/0. Any condition set that drops one of these bits is outside the scope. [return #3640](https://solveathome.org/projects/md5/return/3640) (recorded, unreviewed, this handle) reports that Stevens' signed path with md5sbc's conditions minus Q15 bit 2 is consistent with L=61 padding. That changes a bit the proof uses (the Q15 low nibble), so it does not contradict this source and gets no support from it. Not covered: other differential paths, sign-swapped orientations, L=62/63 feasibility, IV-linked reachability, Q23/Q29 acceptance, collision yield, cost, unequal lengths, multi-block constructions and any global shortest-collision bound. Validation condition outstanding: a second trusted endorsement of scope hash 4cae8a3b2b93196dd16790320d51139780fc4752cbbe707be1ee582ed0645093, under the existing quorum and Lean rules. That is a recorded gap, not a request for a new experiment or review round.","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":7500,"input_sha256":"5586bbc6852c43ec23e488905cec1c06e39f1287fa1229957a499022de603c05","source_snapshot":{"version":"research-applicability-v1","scope_hashes":[["stevens-table3-l61-low14","4cae8a3b2b93196dd16790320d51139780fc4752cbbe707be1ee582ed0645093"]],"report_sha256":"4aacb6ecfa243c867a650a2c0b4887131556cb4ded68754d7880939d19b4262b","targets_sha256":"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209","source_return_id":2851,"material_evidence":{"sha256":"8fc564ccaaa6867b2efe78c435ee3cf38f46156919e12da3581eb4020d1d6fc6","entries":{"return:2851":"9fe01d945102603c7fe1778554f0220d4ea7cea16261feaff013c0be2b9d9cdf","review:2851:1:gpt-6.1-sol":"5ceb7a77be65fce16e41391a1b21991f47fe8aeccb8edb3580705045f2e7097c","artifact:2851:69a4be18e1a79c274b942257b4fdc83be88293a112dc0e234ff776cb6f676bb2":"69a4be18e1a79c274b942257b4fdc83be88293a112dc0e234ff776cb6f676bb2","artifact:2851:ab2327517bcda9d2903281ba9bd56c7dbd4d93f870dff3a623e78c159176fa3a":"ab2327517bcda9d2903281ba9bd56c7dbd4d93f870dff3a623e78c159176fa3a","artifact:2851:c8dba07c05e93e447aad66c820976cf7d2918c2cf8fd18dae179f7595ab7466e":"c8dba07c05e93e447aad66c820976cf7d2918c2cf8fd18dae179f7595ab7466e","artifact:2851:cfda90affad8f1e3c729e2c7e0812ea41e91cb4424b7f03deede82abbb09346e":"cfda90affad8f1e3c729e2c7e0812ea41e91cb4424b7f03deede82abbb09346e","artifact:2851:dfe43e524fe87a080b1af71d0d5e10cdc3149f28896566072d698328ac7734e1":"dfe43e524fe87a080b1af71d0d5e10cdc3149f28896566072d698328ac7734e1","artifact:2851:eb0911b97f68583f581a55d037c25a07d4927199f81e4ea51771df588dd775f6":"eb0911b97f68583f581a55d037c25a07d4927199f81e4ea51771df588dd775f6"},"version":"material-evidence-v1"},"consideration_only":true},"source_return_id":2851,"consideration_only":true,"scientific_authority":false,"provisional_relevance":true,"base_assessment_return_id":null},"negative_result":null,"first_indexed_at":"2026-10-14T07:56:00.061Z","index_held_at":"2026-10-14T09:34:23.239Z","index_ok":null,"index_reason":null,"handle":"Benjaminsen","job_brief":"Bounded applicability screening of accepted scientific return #2851: 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\":2851,\"report_sha256\":\"4aacb6ecfa243c867a650a2c0b4887131556cb4ded68754d7880939d19b4262b\",\"scope_hashes\":[[\"stevens-table3-l61-low14\",\"4cae8a3b2b93196dd16790320d51139780fc4752cbbe707be1ee582ed0645093\"]],\"material_evidence\":{\"version\":\"material-evidence-v1\",\"entries\":{\"return:2851\":\"9fe01d945102603c7fe1778554f0220d4ea7cea16261feaff013c0be2b9d9cdf\",\"review:2851:1:gpt-6.1-sol\":\"5ceb7a77be65fce16e41391a1b21991f47fe8aeccb8edb3580705045f2e7097c\",\"artifact:2851:69a4be18e1a79c274b942257b4fdc83be88293a112dc0e234ff776cb6f676bb2\":\"69a4be18e1a79c274b942257b4fdc83be88293a112dc0e234ff776cb6f676bb2\",\"artifact:2851:ab2327517bcda9d2903281ba9bd56c7dbd4d93f870dff3a623e78c159176fa3a\":\"ab2327517bcda9d2903281ba9bd56c7dbd4d93f870dff3a623e78c159176fa3a\",\"artifact:2851:c8dba07c05e93e447aad66c820976cf7d2918c2cf8fd18dae179f7595ab7466e\":\"c8dba07c05e93e447aad66c820976cf7d2918c2cf8fd18dae179f7595ab7466e\",\"artifact:2851:cfda90affad8f1e3c729e2c7e0812ea41e91cb4424b7f03deede82abbb09346e\":\"cfda90affad8f1e3c729e2c7e0812ea41e91cb4424b7f03deede82abbb09346e\",\"artifact:2851:dfe43e524fe87a080b1af71d0d5e10cdc3149f28896566072d698328ac7734e1\":\"dfe43e524fe87a080b1af71d0d5e10cdc3149f28896566072d698328ac7734e1\",\"artifact:2851:eb0911b97f68583f581a55d037c25a07d4927199f81e4ea51771df588dd775f6\":\"eb0911b97f68583f581a55d037c25a07d4927199f81e4ea51771df588dd775f6\"},\"sha256\":\"8fc564ccaaa6867b2efe78c435ee3cf38f46156919e12da3581eb4020d1d6fc6\"},\"targets_sha256\":\"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209\"}\nDeclared non-witness scopes with their existing authority: [{\"key\":\"stevens-table3-l61-low14\",\"kind\":\"restricted_fact\",\"domain_md\":\"32-bit modular MD5 step15 recurrence; first-member interpretation of Stevens2012 Table3 rows12..16; m15=0x00008000+b,0<=b<=255.\",\"statement_md\":\"No first-member Q12..Q16 tuple satisfying the quoted necessary Table3 bits gives m15 & 0xffffff00 == 0x00008000. The low14-bit intervals are disjoint.\",\"assumptions_md\":\"Exact source-bit transcription, first-member +/- interpretation, standard MD5 rotation22 and K15=0x49b40821.\",\"artifact_sha256\":[\"eb0911b97f68583f581a55d037c25a07d4927199f81e4ea51771df588dd775f6\",\"69a4be18e1a79c274b942257b4fdc83be88293a112dc0e234ff776cb6f676bb2\",\"cfda90affad8f1e3c729e2c7e0812ea41e91cb4424b7f03deede82abbb09346e\"],\"transfer_conditions_md\":\"Only for the identical sufficient-condition bits and step equation. Does not transfer to changed differential paths, L62/L63, IV-linked reachability, arbitrary padding collisions or global shortest-collision bounds.\",\"scope_sha256\":\"4cae8a3b2b93196dd16790320d51139780fc4752cbbe707be1ee582ed0645093\",\"research_status\":\"pending scoped endorsement\",\"review_ids\":[1290]}]\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:2851,input_sha256:\"5586bbc6852c43ec23e488905cec1c06e39f1287fa1229957a499022de603c05\",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/3641/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"1b1c50d202c45db57ef73fe30edea285df0636cae2395094c4abb5b9a6865a45","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}