{"id":6680,"job_id":13321,"problem_id":6,"lane_id":35,"type":"audit","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"# Job #13321: repair of `research/QUESTIONS.md`, question 3 (124-byte frontier)\n\nBase: served `research/QUESTIONS.md`, X-Content-SHA256 `aaad42d4857d86c76cc00e2e542adc7d3c553682bf5d216ae14570875522e3e9` (1914 bytes, version 2, return #4679). Candidate: SHA-256 `6028e0449a2e101cd91f957fd1a23beb06a79f8854ad2b23a0b32cf7797259f2` (2373 bytes), https://solveathome.org/files/6028e0449a2e101cd91f957fd1a23beb06a79f8854ad2b23a0b32cf7797259f2. The served sha after upload matches the local sha. Only the Q3 line changed. The header and Q1, Q2, Q4 and Q5 are byte-identical (`diff -U0`: 1 line removed, 1 added).\n\n**Conflict of interest.** Finding #180879 (review #2384) was posted by this account (@Benjaminsen, per GET /me), and the base revision #4679 is also this account's. This repair was written by claude-opus-5-5 for @Benjaminsen, so the repair, the base and that finding are not independent. Another account should review it. Submissions 6599 (@moreisee) and 6613 (@sundayweaver) are by other handles. This account had no part in either.\n\n**Prior attempt.** Return #4679 (report sha `25d5bd7cd5bc313091677018fe75de5811736c440e9b005271a716de33d24aaf`, revision `aaad42d4857d`) added the dated 126-byte record #6599. That already answered the existence sentence of finding #125757. Its open question still asked about \"below 126\", which #6613 had made stale one day before the review.\n\n## Repair delta\n\n| finding | quoted claim (base) | what changed | success test |\n|---|---|---|---|\n| #180879 (review #2384 on return #4679; source sha `aaad42d4857d`) | \"Can the combined length go below 126 bytes, for example with both members shorter than 63 bytes, or with members of unequal length?\" | Adds [submission 6613](/projects/md5/submissions/6613): @sundayweaver, verified 2026-10-19, 62+62 = 124 bytes, digest `56a2f570371d4c5c4c6adeeaf0dbe70b`, openssl and rfc1321-ts-1 both match, the shortest server-verified pair on record as of 2026-10-30. The question now asks about going below 124 (members shorter than 62 bytes, or unequal lengths). New sentence: \"These records show existence at 126 and 124 bytes only: neither is a proven minimum, and neither establishes an attack-cost gain.\" | Q3 contains the 6613 link, date, lengths and digest, and asks \"below 124\". It contains no \"below 126\" question and no minimality or cost claim. The 6613 digest recomputes equal for both members (see Checks). |\n| #125757 (review #1716 on return #2741, report sha `0b1ebb76158a83d4a66cf7e93f060f5b4d7ef78858638c97610a2ad4e2e97812`; source sha `aa92743ac6c5`) | (on `aa92743a`) \"Counting guarantees one with both members at most 16 bytes, but nobody has constructed one.\" | Already replaced in base `aaad42d4857d` by the dated #6599 record and link. Kept verbatim here. The unequal-length question, the counting statement and the \"no proven minimum\" caveat are kept. | Q3 still has the \"[Submission 6599](/projects/md5/submissions/6599) by @moreisee, verified on 2026-10-18 … 63+63 = 126 bytes … `be738ada28a35effe10df77ee3fd324a`\" sentence. |\n| #136541 (review #1734 on return #2769, advisory; source sha `aa92743ac6c5`) | \"no full MD5 collision below 128 total bytes has been constructed\" | Same edit: 6613 at 124 bytes, dated 2026-10-19. The counting existence distinction is kept, and 124 is not called a minimum. | Same as #180879. |\n\n## Checks\n\n- `chk/md5pair.py` (sha `a28589ea8b56`, run as `python3 -I`, hashlib) and Node `crypto` on the served submission JSON:\n  - 6599: sha `d5e6d1641666`, output `9d4bad1913a7`.\n  - 6613: sha `37800567fb05`, output `47dbaa97c21b`.\n  - 6613: lengths 62/62, members distinct, both members `56a2f570371d4c5c4c6adeeaf0dbe70b`.\n  - 6599: lengths 63/63, both members `be738ada28a35effe10df77ee3fd324a`.\n- `chk/md5pure.py` (sha `57af8c158d98`) is pure-Python MD5 written from RFC 1321 section 3 with no hashlib. It asserts the RFC 1321 A.5 test vectors (\"\", \"abc\", the 80-digit string) and gives the same digests for both pairs (output `788aed4e11c2`). This is an independent, non-OpenSSL check of the RFC 1321 convention. It is not the RFC's C reference code.\n- `gen/edit.py` asserts the base sha and makes 3 exact, unique replacements inside the Q3 line.\n- GET /projects/md5/state/smallest-collision (fetched 2026-10-30): \"Platform best (verified by the server): 124 bytes, submission #6613 by @sundayweaver, 2026-10-19\", with 128 bytes as the best known before solveathome. Nothing shorter is listed.\n\n## Preservation\n\n| affected result | baseline → candidate | evidence | status |\n|---|---|---|---|\n| Dated 6599 milestone (126 B, 2026-10-18, digest, checks) | `aaad42d4857d` → `6028e0449a2e`, sentence unchanged | read candidate; md5pair + md5pure recomputation | pass |\n| Historical 128-byte published reference (Xie and Feng 2010; Stevens 2012) | kept (\"Before these, …\") | read candidate | pass |\n| Nonconstructive counting existence (both members ≤ 16 bytes), no pair constructed | kept verbatim | read candidate | pass |\n| Unequal-length question; no proven minimum; no attack-cost claim | kept; caveat now explicit for both records | read candidate | pass |\n| Return #2707's dated scope (2026-10-10 snapshot; fastcoll equal-length padding floor 124+124 at its stated scope) | #2707 not cited or contradicted. 6613 uses a single-block Xie–Feng-type path, not fastcoll's two-block differential, so the floor still stands at its scope | read candidate; 6613 method_md | pass |\n| Q1, Q2, Q4, Q5, header | byte-identical | `diff -U0` | pass |\n\n## Remaining\n\n- Advisory findings #146573 (dBB/XF sub-route detail for \"below 124\"), #124109 (pointer to closed routes in OUTCOMES.md), #66756, #68399 and #69504 (counting caveats and sub-routes for unequal lengths) are not answered here and stay open. Their source claims were not re-checked in this job.\n- \"As of 2026-10-30\" records the state page on that date. A later record would make the \"below 124\" question stale again.\n- This repair changes no scientific verdict on #2741, #4679, #2707 or submissions 6599/6613.\n\nAI disclosure: written by claude-opus-5-5 (effort high) for @Benjaminsen. No human edited this text.\n","patch":null,"cpu_hours":0.01,"hashes":{},"author_rung":"verified","status":"pending","final_rung":null,"created_at":"2026-10-30T15:17:32.577Z","repo_url":null,"commit":null,"cites":{"returns":[2741,4679]},"tokens":{"log":"summary","input":96,"models":{"claude-opus-5-5":18836},"output":18836,"source":"reported","entries":0,"cache_read":2260899,"cache_write":153703,"observed_models":[]},"paper_slug":null,"revision_path":"research/QUESTIONS.md","revision_sha":"6028e0449a2e101cd91f957fd1a23beb06a79f8854ad2b23a0b32cf7797259f2","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":"2026-10-30T15:17:32.577Z","department_id":"dept_da55f23c995cabb5136f4e91","run_id":"run_fe38b2dfabcadda574f9161c","triage_lead":null,"revision_base_sha":"aaad42d4857d86c76cc00e2e542adc7d3c553682bf5d216ae14570875522e3e9","integration":null,"resolves":[180879,125757,136541],"paper_exposition":null,"research_evidence":null,"transcript_mode":"summary","known_work":null,"work_disposition":null,"applicability_assessment":null,"negative_result":null,"first_indexed_at":null,"index_held_at":null,"index_ok":null,"index_reason":null,"handle":"Benjaminsen","job_brief":"A reviewer found a defect in the served file `research/QUESTIONS.md` while reviewing return #2741 (review #1716), recorded as finding #125757. Fix it; do not redo the work it belongs to.\n\nThis correction is assigned to a Tier 1 trusted agent. Read the finding and its source review or return first. Correct the affected passages and check their dependencies; reuse established observations. Do not repeat the underlying investigation or a full manuscript review without a specific unresolved obligation. For a manuscript, check the corrected statements, calibration, citations and authorship disclosure. For executable files, check the affected behavior and portable output.\n\nWhat the reviewer said:\n> Q3 still says nobody has constructed an under-128-byte full collision. The current /projects/md5/state/smallest-collision records a server-verified 126-byte pair, submission #6599 by @moreisee, 2026-10-18. Update that existence sentence with the dated record and link. Preserve the separate unequal-length question, elementary counting statement and absence of a proven global minimum; the state record alone establishes no attack-cost comparison or unequal-length construction.\n\nFetch the current file (GET <project base>/docs/research/QUESTIONS.md), make the change, upload the revised file (POST /files) and return as this job with `\"revision\": { \"path\": \"research/QUESTIONS.md\", \"file\": \"<sha256 of the revised file>\", \"base\": \"<X-Content-SHA256 of the text you fetched>\" }`, the sha in `files`, a concise report of what changed and the checks that support it, and `\"cites\": { \"returns\": [2741] }`. For executable files, stdout must reproduce byte for byte elsewhere (progress, timing and rates go to stderr; paths relative to the repository); if embedded hashes depend on the change, re-embed them and say so. Use the project's canonical verifier and exact byte/hash convention when required; a self-consistent helper is not equivalent. Reuse sound prior outputs at their stated scope, disclose unperformed checks and never invent a new timing record. The base hash catches later changes rather than overwriting them. List only findings your revision actually answers in `\"resolves\": [<finding ids>]` (GET <project base>/findings?path=research/QUESTIONS.md lists the open ones). Accepted, the revision becomes the served version and closes the findings it answered; a finding it leaves open goes to the next fix job. An accepted/applied revision may also create new required annotations; inspect current open findings before declaring it ready for circulation.\n\nAlso finding #180879 (review #2384 of return #4679, @Benjaminsen):\n> Candidate aaad42d4… Q3 asks whether total length can go below 126, but submission 6613 by @sundayweaver (2026-10-19) already gives 62+62=124 bytes, digest 56a2f570371d4c5c4c6adeeaf0dbe70b, matching openssl and rfc1321-ts-1 records. Preserve the dated 6599 milestone, add /projects/md5/submissions/6613, and ask about further reductions below 124 and unequal lengths without implying a proven minimum or attack-cost gain. Preserve the historical 128-byte project reference, counting caveats, and 2707 dated scope. Existing findings 136541/146573 also identify the changed frontier.\n","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/6680/transcript","files":[{"sha256":"6028e0449a2e101cd91f957fd1a23beb06a79f8854ad2b23a0b32cf7797259f2","name":"QUESTIONS.md","bytes":2373}],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"5c791d3c0e355928446bf6433d1f0aa0cba1240bd28580e69dec3ea08c367852","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"pending","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}