{"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":"541096f2-275d-4591-9a3b-fee5ec11868d","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"edbb30b773f273c1ee13747e9fa5092ed9170c1afb284bb1c4c5f9eede741f5d","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:sha256:24]\nFind a collision for sha256 truncated to the first 48 bits (λ=24).\nReturn a JSON file named collision.json with exactly:\n{\"algo\":\"sha256\",\"lambda\":24,\"inputA\":\"<hex 0x... or utf8>\",\"inputB\":\"<hex 0x... or utf8>\"}\nRules:\n- inputA and inputB must be distinct\n- digest(sha256, inputA) and digest(sha256, 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":"86625dc03c637a82308203516e25acf6912160ac4f045e34c15268626b6b5048","previousHash":"0000000000000000000000000000000000000000000000000000000000000000","projectId":"541096f2-275d-4591-9a3b-fee5ec11868d","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":"51365","feedbackHash":"7ea657804f5e1064692dcdde35d9a430f391efc30207613deb53eb425b7cf013","nodeKey":"research_report","submissionHash":"edbb30b773f273c1ee13747e9fa5092ed9170c1afb284bb1c4c5f9eede741f5d","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"7e95881037a53bb94ba0a75735d9bfa268b80093ce691adb92aa1c09138fde52","state":"completed","submissions":[{"artifacts":[{"bytes":2058,"hash":"0a3c5bf47277710821c54c5bbfe57fa6e2329d012dbe9efdd2b566a80c96c121","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"47ef24a3c3acb04fa5bc89d1b3720210bce4fbee0c0d98c7c72e9eec14402710","device":"6d75e68b68d9d921","findings":[],"hash":"edbb30b773f273c1ee13747e9fa5092ed9170c1afb284bb1c4c5f9eede741f5d","nodeId":"3e9dd025-0942-4cea-b391-f652413063a8","outcome":"completed","summary":"I found a real collision. These two distinct inputs have SHA-256 digests whose first 48 bits match:\n\n```json\n{\"algo\":\"sha256\",\"lambda\":24,\"inputA\":\"imd-12192837\",\"inputB\":\"imd-19093962\"}\n```\n\n- `imd-12192837` hashes to `c94563ba4883`4c66186f…\n- `imd-19093962` hashes to `c94563ba4883`0d17ce78…\n\nThe first 12 hex digits (48 bits) are the same and the rest of the digests differ. Python's `hashlib` and the standard `sha256sum` command gave the same digests, and `tools/verify.py` reports `COLLISION OK`. The remote SIMD verifier wasn't available here, so I haven't run the actual check against it.\n\n**How it was found:** a standard birthday search over strings `imd-<i>` on 4 CPU cores. It found the match after about 19.1 million evaluations (≈2^24.2) in about 46 seconds. That fits the expected ≈2.1·10^7 evaluations for a 48-bit prefix. The search relies only on the output length, so it says nothing about the security of full SHA-256.\n\n**Assumptions:** the verifier reads strings without a `0x` prefix as plain UTF-8 with no trailing newline, and \"first 48 bits\" means the first 6 bytes of the digest. `artifacts/report.md` separates facts, inferences and open questions as the acceptance criteria require.\n\nEverything is left untracked and nothing is committed:\n- **Collision:** `collision.json` at the repo root.\n- **Tools:** `tools/birthday_search.py` (the search) and `tools/verify.py` (re-checks the collision offline using only the Python standard library).\n- **Report:** `artifacts/report.md` and `artifacts/README.md`.","treeHash":"66a8b6c414f8116ae122e69686c8d620a3fce048","usage":{"cachedInputTokens":133884,"inputTokens":14,"model":"claude-opus-5-5","outputTokens":4093,"runtime":"claude","turns":7,"wallClockMs":92906}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"edbb30b773f273c1ee13747e9fa5092ed9170c1afb284bb1c4c5f9eede741f5d","verifiedTreeHash":"66a8b6c414f8116ae122e69686c8d620a3fce048","verifierVersion":"0.1.0+f8d984f2"}]}