{"id":2837,"job_id":5975,"problem_id":6,"lane_id":34,"type":"explore","user_id":76,"model":"auto","provider":"unknown","report_md":"# Job 5975: neutral-bits / message-mod question — covered by return 2801\n\n**Stop condition.** This assignment's obligation is already answered. Return **2801** (job 5911) has a byte-identical `job_brief` (SHA-256 `b0f00d4452e8dfd855ba098f437dad0d1938ee76e86da67c15f87ceb959ab021`) and a measured negative: full-state single-bit \"neutral bits\" through early M4 uses are identically 0 after round 1, and one-pass M4 solve+reinject matches generic search (~16^-k) for leading zeros at L=52.\n\nThis explore is a **known-work consolidation** plus a cheap local random baseline. It makes **no new scientific claim**.\n\n## Covered claim (2801)\n\n1. After step 16 on L=52, 0/416 payload bits leave the full 128-bit state unchanged (30/30 samples).\n2. M4 reinject vs random at N=80,000: H0=0 counts 0 vs 0; score≥1..4 histograms match ~N/16^k.\n\nAlso supported by **2779** (one-pass free-M4 negative) and **2781** (iterative M4 negative).\n\n## Local replay (not a new experiment)\n\nN=20,000 uniform random L=52 `hashlib.md5` (seed `0x5975`):\n\n| k | ge count | expected N/16^k |\n|---|---:|---:|\n| 1 | 1268 | 1250 |\n| 2 | 63 | 78.1 |\n| 3 | 5 | 4.9 |\n| 4 | 1 | 0.3 |\n\nRates match the generic model; no claim beyond custody of the covered question.\n\n## Limits / reopen (from 2801; unchanged)\n\n- **Condition-level** Klima/Stevens neutral bits and Q-tunnels (partial bit conditions) are a different object — not measured by 2801's full-state survey.\n- Multi-block 1 KiB freedom (QUESTIONS Q2) is separate.\n- Reopen only with a constructive differential/tunnel that beats equal-hash generic search, or a documented defect in 2801.\n\n## OUTCOMES.md entry (proposed)\n\n| Track | Method | Budget and hardware | Best reached | Note |\n| --- | --- | --- | --- | --- |\n| All zeros | Known-work: neutral bits + M4 mod (2801) + N=2e4 random replay | ~0.001 CPU-h; aarch64 | incidental | Covered; no new claim |\n","patch":null,"cpu_hours":0.001,"hashes":{"recipe.md":"9c2948af9237d500e09cc7fdde662cee606866fa7749956fe4f28b9d7a24511b","report.md":"0323f83f5c9b9041889b29acf298ff598de2b3304093ef9cbee5f17037435fa8","replay.json":"c72d8a55d538b2f09e62386067504d80edaa9cfc905b041faaf28d4bbca56af6","transcript_summary.md":"fd078612b3c97b73eeef554c7176f7636485906ee2e14554e7b8da52417ec1d2"},"author_rung":"heuristic","status":"recorded","final_rung":"recorded","created_at":"2026-10-10T20:51:15.727Z","repo_url":null,"commit":null,"cites":{"files":["c72d8a55d538b2f09e62386067504d80edaa9cfc905b041faaf28d4bbca56af6","0323f83f5c9b9041889b29acf298ff598de2b3304093ef9cbee5f17037435fa8","9c2948af9237d500e09cc7fdde662cee606866fa7749956fe4f28b9d7a24511b","fd078612b3c97b73eeef554c7176f7636485906ee2e14554e7b8da52417ec1d2"],"handles":[],"returns":[2801,2779,2781,2668],"messages":[]},"tokens":{"log":"summary","input":0,"models":{},"output":0,"source":"none","entries":0,"cache_read":0,"cache_write":0,"observed_models":[]},"paper_slug":null,"revision_path":null,"revision_sha":null,"recipe_md":"# Recipe\n\nObligation text equals return 2801 `job_brief` (SHA-256 `b0f00d4452e8dfd855ba098f437dad0d1938ee76e86da67c15f87ceb959ab021`).\n\nReplay: `python3` uniform random L=52 MD5 for N=20000 seed `0x5975`; counts in `replay.json`.\n\nOr re-read return 2801 report and its `neutral_bits_results.json`.","verification":null,"target":null,"finding":null,"human_md":null,"provisional":false,"effects_applied_at":null,"effort":null,"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_fa6dbf79354b8806abb61eec","run_id":"run_a7419dd35088e539169f2abb","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,"handle":"aasper03","job_brief":"Do neutral bits or message modification from MD5 collision attacks help make the first output word zero? Measure against generic search.","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/2837/transcript","files":[{"sha256":"c72d8a55d538b2f09e62386067504d80edaa9cfc905b041faaf28d4bbca56af6","name":"replay.json","bytes":453},{"sha256":"0323f83f5c9b9041889b29acf298ff598de2b3304093ef9cbee5f17037435fa8","name":"report.md","bytes":1884},{"sha256":"9c2948af9237d500e09cc7fdde662cee606866fa7749956fe4f28b9d7a24511b","name":"recipe.md","bytes":298},{"sha256":"fd078612b3c97b73eeef554c7176f7636485906ee2e14554e7b8da52417ec1d2","name":"transcript_summary.md","bytes":434}],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"0323f83f5c9b9041889b29acf298ff598de2b3304093ef9cbee5f17037435fa8","research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}