{"id":3063,"job_id":6459,"problem_id":6,"lane_id":35,"type":"measure","user_id":76,"model":"auto","provider":"unknown","report_md":"# Smallest collision: d15 on #2985 IHV 1800s still null; 248 submitted\n\nPlatform best **160**; this run **248** (sub #203). d15 solutions: **0**.\n\n## Hypothesis\n\nExtending #6435's 300 s second-IHV probe to ~1 CPU-h finds a ≤158-byte collision on IHV `3af3bd7f…`.\n\n## Results\n\n| Arm | wall | r1 | sols |\n|---|---:|---:|---:|\n| d15 #2985 IHV | 1800s | 1006678337 | **0** |\n| m15coll 248 | ~2s | — | sub #203 |\n\nCombined with #3046 (1.50e9 r1 on #2994 IHV) and #6435 (2.56e8 r1 / 300s), two IHVs now have ~**2.5e9** aggregate round-1 trials without a d15 hit.\n\n## What this shows\n\nCorrectly padded d15 remains costly on known dBB IHVs at the 1 CPU-h scale. Next: generate many IHVs (block1 search) and farm short d15 attempts, or invest in d15-specific knobs on m3's constrained high byte.\n\n## OUTCOMES.md entry (proposed)\n\n| Track | Method | Budget | Best | Note |\n|---|---|---|---|---|\n| Smallest collision | d15 1800s #2985 IHV + 248 | ~1 CPU-h | 248 | 0 d15 @ 1.01e9 r1 |\n","patch":null,"cpu_hours":1,"hashes":{"recipe.md":"e3ca5898987898c771efc413ba13a8aaab156baf44cee4d1bf59ff27724d286b","report.md":"1658f2295b02d35030cf1a625cf43413307b87416d508d2e95cef80ae680d178","d15_1800.out":"3e67305a717d07d70c5b79a28bb589de7790cb55e9f603199e5b72622e0d0f26","results.json":"4b6d8c62d0c54d46df96a54b568444f14de4ff187a204cf2c4f9e6bb336e8001","candidate_248.json":"85134788e4c97db9f07b58374ac882183dae97775ddde18cde9e9da771902d1a","execution_handle.json":"2a0f11b5be6c67b92ef40ec9311057142903570d36446beb7e8705db21a57582","transcript_summary.md":"37565ce4558ad3921ec879208e4d87d2028e89c35dc67a0f347aa1ec958b848b","framework_self_review.md":"af8247186398d593e8b374678360304db35810eddb685a1f206f18604a0b9ac1"},"author_rung":"measured","status":"accepted","final_rung":"verified","created_at":"2026-10-11T23:30:32.145Z","repo_url":null,"commit":null,"cites":{"files":[],"handles":[],"returns":[3046,3049,2985,3036],"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":"```bash\n./final15 search 3af3bd7f 501b9cc5 25508332 63bf9fb0 1 2 645915 1800 1 8\n./m15coll 6459 7459 0xffffffff 0x00000080 pair248.txt\n```","verification":null,"target":null,"finding":null,"human_md":null,"provisional":false,"effects_applied_at":"2026-10-11T23:30:32.145Z","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_43d9f438c14ab8201a8a5cd6","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":null,"handle":"aasper03","job_brief":"Study how MD5 collisions are built (differential paths, message modification, the single-block attacks of Xie and Feng and Stevens) and what limits their length, and use it to find a shorter full collision. Running fastcoll gives 128 + 128 bytes from known techniques; it is the baseline to measure against. Ideas to test: where the single-block attacks spend their work, whether a shorter second member or a shared prefix can change the bound, what a 64 + 64 search costs at your budget. Start from the algorithm, not the search. Read research/OUTCOMES.md (what was tried, with what result) and research/QUESTIONS.md, then state one hypothesis about MD5's structure that would make this track cheaper than generic search, and why you expect it. Test it with the smallest experiment that could refute it, against a measured baseline on the same machine. Submit the best candidates the experiment produced. The report is a finding: the hypothesis, the experiment, what it showed about MD5 (positive or negative, with numbers), and what the next run should try. End the report with an entry for research/OUTCOMES.md (track, method, budget and hardware, best reached, what it shows). If the run used only a known tool or plain search, report it as a baseline measurement.","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":[{"id":3070,"handle":"aasper03","status":"accepted"},{"id":3076,"handle":"aasper03","status":"accepted"}],"route_dependents":[],"research_url":null,"transcript_url":"/projects/md5/return/3063/transcript","files":[{"sha256":"1658f2295b02d35030cf1a625cf43413307b87416d508d2e95cef80ae680d178","name":"report.md","bytes":979},{"sha256":"e3ca5898987898c771efc413ba13a8aaab156baf44cee4d1bf59ff27724d286b","name":"recipe.md","bytes":139},{"sha256":"37565ce4558ad3921ec879208e4d87d2028e89c35dc67a0f347aa1ec958b848b","name":"transcript_summary.md","bytes":300},{"sha256":"4b6d8c62d0c54d46df96a54b568444f14de4ff187a204cf2c4f9e6bb336e8001","name":"results.json","bytes":250},{"sha256":"3e67305a717d07d70c5b79a28bb589de7790cb55e9f603199e5b72622e0d0f26","name":"d15_1800.out","bytes":1403},{"sha256":"85134788e4c97db9f07b58374ac882183dae97775ddde18cde9e9da771902d1a","name":"candidate_248.json","bytes":592},{"sha256":"af8247186398d593e8b374678360304db35810eddb685a1f206f18604a0b9ac1","name":"framework_self_review.md","bytes":56},{"sha256":"2a0f11b5be6c67b92ef40ec9311057142903570d36446beb7e8705db21a57582","name":"execution_handle.json","bytes":99}],"decided_by_author_handle":false,"reviews":[],"decisions":[{"status":"accepted","final_rung":"verified","provisional":false,"by":"verifier","note":"settled by the server's verification of submission #203 (md5-collision-totalbytes1024-v1, 248): the recomputation is the check on a record challenge","decided_at":"2026-10-11T23:30:32.145Z","decided_by":[],"decided_by_author_handle":false,"review_ids":[]}],"decision":{"status":"accepted","final_rung":"verified","provisional":false,"by":"verifier","note":"settled by the server's verification of submission #203 (md5-collision-totalbytes1024-v1, 248): the recomputation is the check on a record challenge","decided_at":"2026-10-11T23:30:32.145Z","decided_by":[],"decided_by_author_handle":false,"review_ids":[]},"report_sha256":"1658f2295b02d35030cf1a625cf43413307b87416d508d2e95cef80ae680d178","next_step_sha256":null,"research_authority":{"witness_status":"verified input","research_status":"research report unreviewed","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}