{"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":"58c352ba-3387-416d-9631-644cb1034225","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"6c564f7e8c4fab00cd6d35a4d2dcea600c2863f9fae3b5d66f62291d7520a9ae","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:ripemd160:25]\nFind a collision for ripemd160 truncated to the first 50 bits (λ=25).\nReturn a JSON file named collision.json with exactly:\n{\"algo\":\"ripemd160\",\"lambda\":25,\"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 50 bits MSB, must be identical\n- Do not invent a false collision; verification is recomputed by SIMD\nBirthday cost is about 2^25 evaluations.","parentJobId":null,"planHash":"938261736615de72e6375ad8a92e0d8d67741f642f8019bedaa6ff08ef286226","previousHash":"0000000000000000000000000000000000000000000000000000000000000000","projectId":"58c352ba-3387-416d-9631-644cb1034225","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":"52598","feedbackHash":"22d8492373d2f169b70bdb488bfe6743fc495d3f8448f954138f31acc6c549a4","nodeKey":"research_report","submissionHash":"6c564f7e8c4fab00cd6d35a4d2dcea600c2863f9fae3b5d66f62291d7520a9ae","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"4f3422dac39f724f185e923f87d1bf522b03141cc336549294966ea6ed88536a","state":"completed","submissions":[{"artifacts":[{"bytes":2397,"hash":"b8cd258f532eab23beefa8ca365bf5ca98158b3c913c58c009d645c25314778e","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"d6577f1ba162c107a3fa5dff6f7cb3659adac6b6c602556ac5da52928a03d833","device":"2b170a76e3d9adca","findings":[],"hash":"6c564f7e8c4fab00cd6d35a4d2dcea600c2863f9fae3b5d66f62291d7520a9ae","nodeId":"790a8ed5-df3e-4a80-b29e-61bc17d08fd3","outcome":"completed","summary":"I found a real collision and checked it two separate ways.\n\n```json\n{\"algo\":\"ripemd160\",\"lambda\":25,\"inputA\":\"imd-6952175\",\"inputB\":\"imd-55049483\"}\n```\n\nBoth inputs are plain UTF-8 text with no trailing newline.\n\n- **`imd-6952175`** hashes to `b6972870fbd64b55df0c43bad001b8f9fd428036`.\n- **`imd-55049483`** hashes to `b6972870fbd668c35f15b2a8b04b95626f232941`.\n- **Match:** both digests start with the same 50 bits (`0x2da5ca1c3ef59`); bit 51 is the first one that differs.\n\n**How it was found:** a Python script, `tools/find_collision.py`, hashed the inputs `imd-0`, `imd-1` and so on until two shared a 50-bit start. It took about 47 seconds on 4 cores and about 55 million hashes, which is close to what this kind of search is expected to need.\n\n**Checks:** Python's `hashlib` and the `openssl dgst -ripemd160` command gave the same digests for both inputs. `hashlib` also returns the published result for an empty input. I recomputed the 50-bit match and that the inputs differ.\n\n**One open point:** I haven't seen the verifier's code. I assumed \"first 50 bits\" means the 50 most significant bits of the digest read in the usual (big-endian) byte order. If the verifier cuts it differently, this pair may not pass. The report lists the full digests so the pair can be checked against any other way of cutting the bits.\n\n**Files:**\n- **Committed (`1b2e115`):** `collision.json`, `tools/find_collision.py` and `README.md`.\n- **Left uncommitted for upload:** `artifacts/report.md`, the required report. It separates facts, assumptions and open questions. `artifacts/collision.json` is a copy of the answer. Git already ignores the `artifacts/` folder, so neither file was added.\n- **Commit author:** git had no author set on this machine, so I used your name and email for that one commit only. Your git settings are unchanged.","treeHash":"40c3e72b228d86d655cea231d8058f6d2fe5b8fa","usage":{"cachedInputTokens":193865,"inputTokens":16,"model":"claude-opus-5-5","outputTokens":5704,"runtime":"claude","turns":8,"wallClockMs":108900}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"6c564f7e8c4fab00cd6d35a4d2dcea600c2863f9fae3b5d66f62291d7520a9ae","verifiedTreeHash":"40c3e72b228d86d655cea231d8058f6d2fe5b8fa","verifierVersion":"0.1.0+fb8278c5"}]}