{"assessments":[],"deployments":[],"fuzz":[],"identity":{"adapter":"0xde152afb7db5373f34876e1499fbd893a82dd336","chainId":1,"collection":"0x0000ec93127baa929e58e97dd0095a2bfb38ec1d","registry":"0x8004a169fb4a3325136eb29fa0ceb6d2e539a432"},"interpretation":"Records acceptance and evidence. Neither completion nor an AI assessment establishes correctness, safety, or independent review.","jobId":"1885e5d3-d51c-4377-9135-29d3ef0d449f","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"fc9a1ceea3c87ffe71812a4a509e551abb60b29056faee50688f50e92299c95e","dependsOn":[],"execution":{"network":true,"profile":"none","requires":["network"],"skillHash":"3ddca93330036359dd721585e58e67820336a0398b7927b3c89369d6134f30f6","skillId":"research-report","tools":[]},"key":"research_report","kind":"code","role":"implement","skillHash":"3ddca93330036359dd721585e58e67820336a0398b7927b3c89369d6134f30f6","skillId":"research-report","state":"accepted"}],"objective":"[SIMD-COLLISION:ripemd160:24]\nFind a collision for ripemd160 truncated to the first 48 bits (λ=24).\nReturn a JSON file named collision.json with exactly:\n{\"algo\":\"ripemd160\",\"lambda\":24,\"inputA\":\"<hex 0x... or utf8>\",\"inputB\":\"<hex 0x... or utf8>\"}\nRules:\n- inputA and inputB must be distinct\n- digest(ripemd160, inputA) and digest(ripemd160, inputB), truncated to 48 bits MSB, must be identical\n- Do not invent a false collision; verification is recomputed by SIMD\nBirthday cost is about 2^24 evaluations.","parentJobId":null,"planHash":"db8cf59269792af61e6af2b5ee3f86a9745dd031d74535fb14290fe873f6a5ff","previousHash":"0000000000000000000000000000000000000000000000000000000000000000","projectId":"1885e5d3-d51c-4377-9135-29d3ef0d449f","publication":{"commit":null,"deliveredAt":null,"repoUrl":null},"receiptIdentity":{"adapter":"0xde152afb7db5373f34876e1499fbd893a82dd336","chainId":1,"collection":"0x0000ec93127baa929e58e97dd0095a2bfb38ec1d","registry":"0x8004a169fb4a3325136eb29fa0ceb6d2e539a432"},"registry":"0xb6d0a187b050fa5bb0b87033a203f37becf4a775","research":[],"schema":"identitymd-work-v1","signals":[{"agentId":"51982","feedbackHash":"9f3c814a96033361100e711d840d8cbaac74d69eea938f0840e06c352240c0c4","nodeKey":"research_report","submissionHash":"fc9a1ceea3c87ffe71812a4a509e551abb60b29056faee50688f50e92299c95e","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"830598b84af84bc1539d5aa81f62883404502e66967ea2fce357572aa568d24c","state":"completed","submissions":[{"artifacts":[{"bytes":2474,"hash":"30c70b396a882b20b679e51d737e9e87b56a4cff0b45fd90ba4fd2b17c2e76b7","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"a83985e3eac75da3d3f4e127431c048995bf78f3da0320a1fd9b92c773927059","device":"99ae6f7a51d4ac9b","findings":[],"hash":"fc9a1ceea3c87ffe71812a4a509e551abb60b29056faee50688f50e92299c95e","nodeId":"0a155924-68da-4113-b084-33f0a30cfc62","outcome":"completed","summary":"I found a real collision. The two inputs below give RIPEMD-160 digests that match on the first 48 bits.\n\n**`collision.json`** (committed at the repo root):\n```json\n{\"algo\":\"ripemd160\",\"lambda\":24,\"inputA\":\"imd-70e373fa6b0c\",\"inputB\":\"imd-4a68f5e58b32\"}\n```\n\n| Input (UTF-8) | RIPEMD-160 digest |\n|---|---|\n| `imd-70e373fa6b0c` | **`6754b6bedcc2`**`0d1f056655815402ccc730cfe019` |\n| `imd-4a68f5e58b32` | **`6754b6bedcc2`**`e8469fe77a98de29629c6d1eb47c` |\n\n**How I checked it:** Python's `hashlib` and `openssl dgst -ripemd160` gave the same full digests for both inputs. `hashlib` also returns the published RIPEMD-160 test value for the empty string. My checking script printed `OK`. I have not run it through the SIMD verifier.\n\n**How I found it:** I used a cycle-finding search (Floyd's method) that needs almost no memory. It took about 14 million hash computations and 17 seconds in Python, slightly under the expected 2^24-scale cost. It is a generic birthday search and does not use any weakness in RIPEMD-160.\n\n**Uncertainty:** the inputs have no `0x` prefix, so they should be read as UTF-8 text. If the verifier treats unprefixed strings as hex instead, it will hash different bytes and reject the pair.\n\nOther files:\n- **`README.md`**: the question, the answer and the limits (committed).\n- **`tools/find_collision.py`** and **`tools/verify_collision.py`**: the search and the checking script (committed).\n- **`artifacts/report.md`**: the full report, which separates facts, inferences and open questions. It is untracked as instructed (`.git/info/exclude` already ignores `artifacts/`).\n\nGit had no author identity configured, and I'm not allowed to edit `.git/`. So I passed one for this commit only, using your account email.","treeHash":"130148ab33dc550ed2eacfe515bdaa039c769211","usage":{"cachedInputTokens":167414,"inputTokens":16,"model":"claude-opus-5-5","outputTokens":5455,"runtime":"claude","turns":8,"wallClockMs":74999}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"fc9a1ceea3c87ffe71812a4a509e551abb60b29056faee50688f50e92299c95e","verifiedTreeHash":"130148ab33dc550ed2eacfe515bdaa039c769211","verifierVersion":"0.1.0+41305fb5"}]}