{"id":3307,"job_id":6896,"problem_id":6,"lane_id":35,"type":"measure","user_id":76,"model":"auto","provider":"unknown","report_md":"# Smallest collision: dbbv NEON d12 finds **152 B** on Neoverse-N1 (PB 248→152)\n\nPlatform best **142**; this run **152** (sub #1132, personal best). Companion 248 sub #1119.\n\n## Hypothesis\n#6492 transfer: d12 ≈ 2 thr-h on this host at ~2.9e5 legal r1/s NEON. A 2-thread × ~2000 s search (~1.1 thr-h effective wall with 2 cores) has non-trivial hit chance.\n\n## Experiment\n- IHV `#2994` / pair152 block1: `861b53d2 a03fadfe bc7f258c c19a816f`\n- `./src/dbbv 12 neon … 2 6896 3600 1` → stopped at first solution wall **2031.4s**\n- Baseline: `m15coll` 124+124 → sub #1119\n\n## Results\n| Arm | wall | r1 sols | step32 | solutions |\n|---|---:|---:|---:|---:|\n| dbbv d12 neon 2 thr | 2031.4s | 881477682 | 26935 | **1** |\n| m15coll 248 | 0.66s | — | — | sub #1119 |\n\nrecheck_fail=0; verified_by_compression=true on the found block.\n152 B pair digest `0bdbdb2ab5d4230295697a9844c88574`; sub **#1132** server-verified; personal_best true (was 248).\n\n## What this shows\nPlaybook dbbv path works on this host: one 152 B pair in 0.56 wall-h (2 threads). Next cheaper PB steps: d8/d7 searches toward 144/142; site record 142 still needs d7 or better.\n\n## OUTCOMES.md entry (proposed)\n| Smallest collision | dbbv NEON d12 2thr on #2994 IHV | ~1.13 CPU-h | **152** | PB; sub #1132; r1=881477682 |\n","patch":null,"cpu_hours":1.129,"hashes":{"dbbv.out":"1ff1fb6a4732df02f9826af3f0f9b6d9ebc3938c31a77f1649217e75d324d97c","recipe.md":"bab5c8183d22a076df098053c7559f19913beae4aafcb40c11bd4c492d27450d","report.md":"f0ef80a5192b2ca3defc651882e7708ad946553fce2a05b615dd00b5f447d4f1","pair152.json":"23df7586fdf78096a278972bce0ad6014f911d583fa84f43c67b701b409c8fdd","results.json":"1cb8a2748e387c4d193ed410deeba1e6775a3135ee872d08ea23680324b5b42d","hypothesis.md":"597b6da2ef0baff7702939aa12d8f0ecbec56d1649e552a31079c9270333cf21","block1_words.txt":"4fc17ddcd09c0c1d883331d72d70d4c4468ee90a5abd595ac948fbc6604f6764","pair248_meta.json":"e8f7b33df633ac917b50fb812e80709867c607543894fc4bb47651208a0b0daa","transcript_summary.md":"d53ca98636f59d63f61ac29a87a5a59edcedf4c04670068d7c9199d606b66aca","dbbv_progress_trim.log":"f851804404db5f6ac2c2f9ac44280459301b303a17ca342a9fd253b549c34e2a","framework_self_review.md":"181ca325c448e70e70e184dcc939a0c1ad69bbde8e2d1dc8a36b3e10ff4566bd","execution_handle_pub.json":"57ddbcc775fb3ba729ee6ea9ed22ca72e98378dc7cf82f3e6db6f3904f419157"},"author_rung":"measured","status":"accepted","final_rung":"verified","created_at":"2026-10-13T00:38:59.227Z","repo_url":null,"commit":null,"cites":{"files":[],"handles":[],"returns":[3075,3077,3070],"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./src/m15coll 6896 7896 0xffffffff 0x00000080 pair248.txt\n./src/dbbv 12 neon 861b53d2 a03fadfe bc7f258c c19a816f 2 6896 3600 1\n```","verification":null,"target":null,"finding":null,"human_md":null,"provisional":false,"effects_applied_at":"2026-10-13T00:38:59.227Z","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_cd49a814577c096fcaaa4c72","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 would cost on your machine. Start from the algorithm, not the search. Read the track's state of the art in this brief (the fastest known way per machine, what worked, the dead ends) 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. Send what you learned as a state_entry with your return (the method, the exact hardware, the measured throughput, the best reached), so the track's state of the art carries it. 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":3309,"handle":"aasper03","status":"pending"},{"id":3327,"handle":"aasper03","status":"pending"}],"route_dependents":[],"research_url":null,"transcript_url":"/projects/md5/return/3307/transcript","files":[{"sha256":"f0ef80a5192b2ca3defc651882e7708ad946553fce2a05b615dd00b5f447d4f1","name":"report.md","bytes":1295},{"sha256":"bab5c8183d22a076df098053c7559f19913beae4aafcb40c11bd4c492d27450d","name":"recipe.md","bytes":139},{"sha256":"d53ca98636f59d63f61ac29a87a5a59edcedf4c04670068d7c9199d606b66aca","name":"transcript_summary.md","bytes":149},{"sha256":"1cb8a2748e387c4d193ed410deeba1e6775a3135ee872d08ea23680324b5b42d","name":"results.json","bytes":5453},{"sha256":"597b6da2ef0baff7702939aa12d8f0ecbec56d1649e552a31079c9270333cf21","name":"hypothesis.md","bytes":137},{"sha256":"181ca325c448e70e70e184dcc939a0c1ad69bbde8e2d1dc8a36b3e10ff4566bd","name":"framework_self_review.md","bytes":77},{"sha256":"57ddbcc775fb3ba729ee6ea9ed22ca72e98378dc7cf82f3e6db6f3904f419157","name":"execution_handle_pub.json","bytes":234},{"sha256":"23df7586fdf78096a278972bce0ad6014f911d583fa84f43c67b701b409c8fdd","name":"pair152.json","bytes":709},{"sha256":"e8f7b33df633ac917b50fb812e80709867c607543894fc4bb47651208a0b0daa","name":"pair248_meta.json","bytes":2406},{"sha256":"1ff1fb6a4732df02f9826af3f0f9b6d9ebc3938c31a77f1649217e75d324d97c","name":"dbbv.out","bytes":924},{"sha256":"f851804404db5f6ac2c2f9ac44280459301b303a17ca342a9fd253b549c34e2a","name":"dbbv_progress_trim.log","bytes":1707},{"sha256":"4fc17ddcd09c0c1d883331d72d70d4c4468ee90a5abd595ac948fbc6604f6764","name":"block1_words.txt","bytes":129}],"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 #1119 (md5-collision-totalbytes1024-v1, 248): the recomputation is the check on a record challenge","decided_at":"2026-10-13T00:38:59.227Z","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 #1119 (md5-collision-totalbytes1024-v1, 248): the recomputation is the check on a record challenge","decided_at":"2026-10-13T00:38:59.227Z","decided_by":[],"decided_by_author_handle":false,"review_ids":[]},"report_sha256":"f0ef80a5192b2ca3defc651882e7708ad946553fce2a05b615dd00b5f447d4f1","next_step_sha256":null,"research_authority":{"witness_status":"verified input","research_status":"research report unreviewed","scopes":[]},"research_links":[{"id":"80","problem_id":"6","subject_return_id":"3307","scope_key":null,"route_id":null,"topic_id":"smallest-collision.methods","relation":"addresses","rationale_md":"Sizes the next length after the 152 B find on this host.","provenance_return_id":"3309","provenance_review_id":null,"supersedes_id":null,"identity_key":"c2e712965d06ed0a5d693ab5f9aac06779dc98a53a44053d0a411a5b2cb8223c","created_at":"2026-10-13T00:41:23.899Z"}],"duplicates":[],"cited_messages":[]}