{"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":"5937363f-a7e4-4950-9259-ce4f08d00f3f","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"352363650ed1e8143026956902a91b57524c8b3db0beaaeb6ccc60670d9a0f13","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":"5937363f-a7e4-4950-9259-ce4f08d00f3f","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":"51021","feedbackHash":"f0ca7aa8e35a1ba77105dcac3fe1e99d696e404f517f987b13b55a11fce5ebd5","nodeKey":"research_report","submissionHash":"352363650ed1e8143026956902a91b57524c8b3db0beaaeb6ccc60670d9a0f13","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"04517299d81cae41ea37c91346872be8fb0c14639b7843cef0ed2566eaa560fc","state":"completed","submissions":[{"artifacts":[{"bytes":2864,"hash":"7f7d92d20bc3ce444ea633e66e7c951d7a018bb24c63b868af1d9f18409773a8","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"d72df187e6ae116873e6cb077b839da411914a6b121ba3a88b5729f67749d077","device":"72ae9b5bbd1a54b6","findings":[],"hash":"352363650ed1e8143026956902a91b57524c8b3db0beaaeb6ccc60670d9a0f13","nodeId":"9dedb8e5-d1b0-4f14-b9a9-811449db2d95","outcome":"completed","summary":"I found a real collision: two different inputs whose SHA-256 hashes share the same first 48 bits.\n\n```json\n{\"algo\":\"sha256\",\"lambda\":24,\"inputA\":\"imd-12192837\",\"inputB\":\"imd-19093962\"}\n```\n\n- **Proof:** both inputs, read as plain UTF-8 text, produce a SHA-256 hash starting with `c94563ba4883`. I recomputed this with Python's `hashlib`, `sha256sum` and `openssl`, and all three agree. The full hashes differ after those 48 bits, so this is a collision on the shortened hash only, as the task asks.\n- **How:** a simple birthday search over the inputs `imd-0`, `imd-1`, … found the first repeat at about 19.1 million hashes (about 2^24.2). That matches the expected cost of about 21 million. It took about 66 seconds on one core.\n- **Not tested:** I did not run the external SIMD verifier.\n- **Assumption:** \"first 48 bits\" means the first 6 bytes of the standard digest.\n\nEverything is left uncommitted. `collision.json` sits at the repo root, with a copy and the report in `artifacts/`.\n\nFiles are in the repo root:\n- `collision.json`\n- `README.md` — the question, the answer and its limits\n- `artifacts/collision.json`\n- `artifacts/report.md` — evidence, method, inferences and open questions, kept separate\n- `scripts/find_collision.py` — the search\n- `scripts/verify_collision.py` — re-checks the pair from a JSON file","treeHash":"58fb0687f3272210edff7aa470554450ebb1bdcb","usage":{"cachedInputTokens":194644,"inputTokens":14,"model":"claude-opus-5-5","outputTokens":3965,"runtime":"claude","turns":8,"wallClockMs":114068}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"352363650ed1e8143026956902a91b57524c8b3db0beaaeb6ccc60670d9a0f13","verifiedTreeHash":"58fb0687f3272210edff7aa470554450ebb1bdcb","verifierVersion":"0.1.0+41305fb5"}]}