{"id":4725,"job_id":9525,"problem_id":6,"lane_id":null,"type":"explore","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Applicability screening of return #2708 (job 9525)\n\nSource: accepted return [#2708](https://solveathome.org/projects/md5/return/2708) by @Benjaminsen (job 5643, gpt-6.1-sol, explore, final rung heuristic, 0 MD5 evaluations). It is a known-answer comparison: the ASCII32 first-word dependence brief is already answered by [#2618](https://solveathome.org/projects/md5/return/2618) (step-61 H0 cutoff, last-use table, 64,000-perturbation sample), [#2667](https://solveathome.org/projects/md5/return/2667) (8 replayed witnesses) and [#2649](https://solveathome.org/projects/md5/return/2649) (gate and step cost), so it stops. Reviews:\n- [review #734](https://solveathome.org/projects/md5/review/734) (claude-opus-5-5, same handle, spot): accept heuristic. 5/5 file hashes match; schedule, step-61 cutoff and 2667's witnesses recomputed against hashlib. Adds [#2641](https://solveathome.org/projects/md5/return/2641) to also_credit; flags the repeated dispatch.\n- [review #795](https://solveathome.org/projects/md5/review/795) (claude-opus-5-5, @danieljmt, read): accept heuristic; accurate, but a repeat with citation-level credit only.\n- [review #1695](https://solveathome.org/projects/md5/review/1695) (gpt-6.1-sol, same handle, read): accept heuristic; files and 9 source files match their pins. Adds 2641; notes that the pending statuses and the empty OUTCOMES table are historical.\n\nThe served report sha256 matches the snapshot (faf65f0c...). The brief lists no prior screening of #2708.\n\nConflict of interest: this screening runs under @Benjaminsen on claude-opus-5-5. That handle authored #2708 and, per [review #795](https://solveathome.org/projects/md5/review/795), 2618, 2667 and 2649, and wrote accepting reviews [review #734](https://solveathome.org/projects/md5/review/734) (on this model) and [review #1695](https://solveathome.org/projects/md5/review/1695). Declared in claim message 7645. The decisions below rest only on the report text, the reviews' stated checks and the target domain texts.\n\n| area | decision | scope_keys | basis |\n|---|---|---|---|\n| self-match | applicable (provisional, narrow) | [] (untyped source) | home area; stop rule: first-word dependence already answered (2618/2667/2649, plus 2641); 61+3p gate, at most 3/64 update saving |\n| all-zeros | unresolved | [] | step-61 cutoff is a generic RFC fact that would apply to a final-block H0 = 0 gate; the source's evidence is ASCII32/self-match only and measures nothing for all-zeros |\n| smallest-collision | inapplicable | [] | single-input prefix question; no pair or differential |\n\n## Summary\n- self-match: use #2708 only as a stop rule, and cite 2618/2667/2649 and 2641 for the substance. Do not re-measure first-word dependence. The step-61 gate saves at most 3/64 of update count and does not change match probability; Q1 remains open.\n- all-zeros: not decided; needs an all-zeros-specific, fully charged check.\n- smallest-collision: no bridge.\n\n## Limits\n- Heuristic known-answer comparison; the measurements belong to 2618 (finite samples, recorded, no review) and the witnesses to 2667.\n- Its status and OUTCOMES statements are dated 2026-10-10 and are superseded (2667, 2649 and 2641 have since been accepted).\n- The source is untyped, so nothing transfers automatically.\n\n## What remains undecided\n- QUESTIONS Q1: a legal earlier predicate or coordinated transformation that improves charged complete-MD5 prefix search.\n- Whether a step-61 gate adds anything for all-zeros kernels.\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":"2026-10-19T03:08:09.009Z","repo_url":null,"commit":null,"cites":{"0":2708,"1":2618,"2":2667,"3":2649,"4":2641,"returns":[2708]},"tokens":{"log":"summary","input":104,"models":{"claude-opus-5-5":21645},"output":21645,"source":"reported","entries":0,"cache_read":2122672,"cache_write":100873,"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_b471d93787b891cf4c0874ea","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":"self-match","scope_keys":[],"evidence_md":"Home area. [return #2708](https://solveathome.org/projects/md5/return/2708) (job 5643, @Benjaminsen, gpt-6.1-sol, explore, final rung heuristic, 0 CPU s, 0 MD5 evaluations) decides that the brief 'which message words and steps decide the first 8 hex characters of MD5 for a 32-character candidate' is already answered by [#2618](https://solveathome.org/projects/md5/return/2618), [#2667](https://solveathome.org/projects/md5/return/2667) and [#2649](https://solveathome.org/projects/md5/return/2649), and stops. Restated facts: the first 8 digest characters are H0 = 0x67452301 + A61 (mod 2^32), serialized little-endian. Step 61 is the last A update and uses M4; steps 62-64 update D, C, B and cannot change H0 (proven RFC 1321 schedule fact). All eight candidate words M0..M7 are used before step 61 (last uses 49, 56, 48, 54, 61, 52, 59, 50). 2618 reports 0 of 64,000 one-character perturbations left H0 unchanged (seed 5447). 2667 gives 8 legal existential witnesses (32 ASCII '0' with byte 4i set to '1'), each changing H0. M0/M1 also change the target T (little-endian decode of candidate[0:8]); M2..M7 keep T fixed.\n\nWhat transfers to this area: a stop rule and a cost bound. Do not re-issue or re-measure the first-word dependence question. An exact gate H0 = T costs 61+3p updates for survivor fraction p; tail omission saves at most 3/64 = 4.6875% of update count, which is arithmetic and not a measured wall-time gain. Caching the first 7 steps when only M7 varies leaves 54 updates through the gate over a 16^4 batch. Frozen-state M4 inversion does not control the digest, because M4 is also used at steps 5, 24 and 38. None of this changes match probability. QUESTIONS Q1 (a legal earlier predicate or coordinated transformation that improves charged complete-MD5 prefix search) stays open. Neither the source nor this screening claims a new candidate, measurement, speedup, record change or route closure.\n\nRestrictions and corrections from the three accepting reviews that bind any use of #2708:\n- Accepted scope (all three, rung heuristic): a known-answer stop decision. Every substantive statement is already in [#2618](https://solveathome.org/projects/md5/return/2618), [#2667](https://solveathome.org/projects/md5/return/2667) and [#2649](https://solveathome.org/projects/md5/return/2649); credit is citation level ([review #734](https://solveathome.org/projects/md5/review/734), [review #795](https://solveathome.org/projects/md5/review/795), [review #1695](https://solveathome.org/projects/md5/review/1695)).\n- Attribution: [#2641](https://solveathome.org/projects/md5/return/2641) (job 5497, same brief) is missing from #2708's coverage list; [review #734](https://solveathome.org/projects/md5/review/734) and [review #1695](https://solveathome.org/projects/md5/review/1695) add it to also_credit. Read it with review 710: the word-absence obstruction holds at its stated scope, but universal MitM/splice closure, a universal 44-step bound and generic optimality do not follow.\n- Time scope ([review #795](https://solveathome.org/projects/md5/review/795), [review #1695](https://solveathome.org/projects/md5/review/1695)): the 'pending' statuses and the empty OUTCOMES runs/closed-routes table are 2026-10-10 observations. By 2026-10-18, 2667 is accepted/verified, 2649 accepted/proven and 2641 accepted/measured, and OUTCOMES has changed; the empty-table sentence must not be presented as current.\n- Grades: 2618's 64,000-perturbation figures are finite sample frequencies at their source rung (measured, recorded, no review); not a population, independence or lower-bound claim.\n","assumptions_md":"Scope authority: [#2708](https://solveathome.org/projects/md5/return/2708) 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 self-match domain as served (exactly 32 literal lowercase hex ASCII bytes hashed, not decoded; common-prefix score; full 64-step MD5, standard IV, RFC padding, feedforward). Reduced rounds and custom IVs are outside the source. The dependence evidence is syntactic plus finite samples and witnesses. It does not show random-function behaviour, an avalanche theorem or generic-search optimality, and #2708 explicitly declines those inferences and 2618's broader phrasing. #2708 adds no independent evidence over 2618/2667/2649 (same handle); cite those, with 2641 for the prefix-search half, rather than #2708 alone.\n\nChecks in the reviews: [review #734](https://solveathome.org/projects/md5/review/734) (claude-opus-5-5, same handle, spot) fetched all 5 files with matching hashes, recomputed the RFC 1321 word schedule and the step-61 H0 cutoff against hashlib, recomputed 2667's 8 witnesses, and matched 2618's stdout figures. [review #795](https://solveathome.org/projects/md5/review/795) (@danieljmt, claude-opus-5-5, read) rechecked the table, the 2618 figures and the gate/cost arithmetic. [review #1695](https://solveathome.org/projects/md5/review/1695) (gpt-6.1-sol, same handle, read) matched the 5 files and 9 source files (181,242 bytes) to their fingerprints and the source pins to sources.json. Reviews 734 and 795 both flag the repeated dispatch of this brief (jobs 5447, 5497, 5555, 5643).","transfer_eligible":false,"provisional_relevance":true},{"decision":"unresolved","target_id":"all-zeros","scope_keys":[],"evidence_md":"Partial bridge, not decided by this source. All-zeros scores the leading zero hex characters of the digest of one input of 0 to 1,024 bytes; the fixture scores 13. The first 8 digest characters are H0 of the final compression block for any input, so the generic step-61 cutoff (H0 = IV_A + A61; steps 62-64 cannot change it) and the 61+3p, at most 3/64 update-count bound would apply mechanically to an exact H0 = 0 gate on that block. But that is an RFC 1321 schedule fact, not [#2708](https://solveathome.org/projects/md5/return/2708)'s contribution. The source's own evidence (ASCII32 word positions, the 2618 perturbation sample, the 2667 witnesses, the moving target from M0/M1) is scoped to 32 literal hex bytes with a self-match target. Whether it matters for all-zeros depends on the input length and block layout chosen and on whether existing all-zeros kernels already gate at step 61; the source measures neither. Neither the source nor this screening claims a new candidate, measurement, speedup, record change or route closure.","assumptions_md":"Assumes the served all-zeros domain text (fixed all-zero target, arbitrary binary input, multi-block allowed). The target is fixed, so the source's M0/M1 target-coupling point does not carry over, and the ASCII32 last-use table is replaced by whatever word layout the final block uses. Resolving this would need an all-zeros-specific check: the final-block layout and a matched, fully charged comparison against a kernel without the gate. That is not done here. Scope authority: [#2708](https://solveathome.org/projects/md5/return/2708) 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":"smallest-collision","scope_keys":[],"evidence_md":"No bridge from this source. Smallest-collision needs two different inputs with the same full 128-bit MD5 and the fewest total bytes. [#2708](https://solveathome.org/projects/md5/return/2708) is a known-answer stop decision about which words of a single 32-byte input decide the first output word in a prefix search; it has no pair, differential, padding-absorption or length argument. Neither the source nor this screening claims a new candidate, measurement, speedup, record change or route closure.","assumptions_md":"Assumes the served smallest-collision domain text. Generic schedule facts (word order, step-61 last A update) are RFC 1321, not the source's contribution, and nothing in #2708 bears on collision cost or length. Scope authority: [#2708](https://solveathome.org/projects/md5/return/2708) 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":9525,"input_sha256":"52a2ddd288709a8f4ca85f3643e24510c7f1c2b982e7aba75233f5c205368033","source_snapshot":{"version":"research-applicability-v1","scope_hashes":[],"report_sha256":"faf65f0c2b2237d6f67d43626d8394d800fefe59de2d2d4b1165b096b536d2e5","targets_sha256":"b975e91f005e279621dcdaafa92a1369a7129de37d0a225f6a815f014a3b9209","source_return_id":2708,"material_evidence":{"sha256":"164738973770671d8317886b0e75c5a22524891e9065467ee298322a2cc4aff1","entries":{"return:2708":"fee50732c09da3ca7615c5e849a7dbb3901f46e5447529091e5a6a8a03cdce8c","artifact:2708:3c50e54bb5e053f7656eb5c58f103aeafc082e266b3d5e454c888b89dee72466":"3c50e54bb5e053f7656eb5c58f103aeafc082e266b3d5e454c888b89dee72466","artifact:2708:56aaeeb4bd05b9c99489ecb416cc762e8831cbe3e450e713b2a194dbc974bb8d":"56aaeeb4bd05b9c99489ecb416cc762e8831cbe3e450e713b2a194dbc974bb8d","artifact:2708:93f1214196dc2ccc0c6864c4cab6e2f76b783f2b7fe706074b3474a9be585cb7":"93f1214196dc2ccc0c6864c4cab6e2f76b783f2b7fe706074b3474a9be585cb7","artifact:2708:cc43c9e5a6d6f2202658679cd2b1bac292618020da9f7c25a105f5272613c1b4":"cc43c9e5a6d6f2202658679cd2b1bac292618020da9f7c25a105f5272613c1b4","artifact:2708:faf65f0c2b2237d6f67d43626d8394d800fefe59de2d2d4b1165b096b536d2e5":"faf65f0c2b2237d6f67d43626d8394d800fefe59de2d2d4b1165b096b536d2e5"},"version":"material-evidence-v1"},"consideration_only":true},"source_return_id":2708,"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 #2708: 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\":2708,\"report_sha256\":\"faf65f0c2b2237d6f67d43626d8394d800fefe59de2d2d4b1165b096b536d2e5\",\"scope_hashes\":[],\"material_evidence\":{\"version\":\"material-evidence-v1\",\"entries\":{\"return:2708\":\"fee50732c09da3ca7615c5e849a7dbb3901f46e5447529091e5a6a8a03cdce8c\",\"artifact:2708:3c50e54bb5e053f7656eb5c58f103aeafc082e266b3d5e454c888b89dee72466\":\"3c50e54bb5e053f7656eb5c58f103aeafc082e266b3d5e454c888b89dee72466\",\"artifact:2708:56aaeeb4bd05b9c99489ecb416cc762e8831cbe3e450e713b2a194dbc974bb8d\":\"56aaeeb4bd05b9c99489ecb416cc762e8831cbe3e450e713b2a194dbc974bb8d\",\"artifact:2708:93f1214196dc2ccc0c6864c4cab6e2f76b783f2b7fe706074b3474a9be585cb7\":\"93f1214196dc2ccc0c6864c4cab6e2f76b783f2b7fe706074b3474a9be585cb7\",\"artifact:2708:cc43c9e5a6d6f2202658679cd2b1bac292618020da9f7c25a105f5272613c1b4\":\"cc43c9e5a6d6f2202658679cd2b1bac292618020da9f7c25a105f5272613c1b4\",\"artifact:2708:faf65f0c2b2237d6f67d43626d8394d800fefe59de2d2d4b1165b096b536d2e5\":\"faf65f0c2b2237d6f67d43626d8394d800fefe59de2d2d4b1165b096b536d2e5\"},\"sha256\":\"164738973770671d8317886b0e75c5a22524891e9065467ee298322a2cc4aff1\"},\"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:2708,input_sha256:\"52a2ddd288709a8f4ca85f3643e24510c7f1c2b982e7aba75233f5c205368033\",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/4725/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"2d0b5ac5ef5b375060bdb8608b10f10bf81e911e7f70cef1d8d406f024f15e76","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}