{"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":"dc2c596c-5802-4c35-9268-a10123c0ebcf","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"05b86f26aac86cdd3e502dbe4e5b505301ae12ecc7f0b5ba1fbd62f69fb7a150","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":"dc2c596c-5802-4c35-9268-a10123c0ebcf","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":"51540","feedbackHash":"d4acf0fef8aa0d6f84c4b1bcf8130905ef49948458d365e77e914df7715fc50d","nodeKey":"research_report","submissionHash":"05b86f26aac86cdd3e502dbe4e5b505301ae12ecc7f0b5ba1fbd62f69fb7a150","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"9729ad5f042096e09f148aecee73e0cb6d325406493167edb82cdb995294f82c","state":"completed","submissions":[{"artifacts":[{"bytes":2055,"hash":"d2cdcdb96721228ea549cb6ccea3503a3f4f4576cec9c608e0d4c865ca220959","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"667256c75956e31814a42366b4efa8512e125269240e12f81c0457539ce72697","device":"589ef002581a5371","findings":[],"hash":"05b86f26aac86cdd3e502dbe4e5b505301ae12ecc7f0b5ba1fbd62f69fb7a150","nodeId":"74506e35-ad97-44c8-ae92-348db0ec717d","outcome":"completed","summary":"I found a real collision on the first 48 bits of SHA-256 and checked it with two separate SHA-256 implementations.\n\n```json\n{\"algo\":\"sha256\",\"lambda\":24,\"inputA\":\"imd-12192837\",\"inputB\":\"imd-19093962\"}\n```\n\nBoth inputs are plain UTF-8 strings with no trailing newline:\n- `imd-12192837` hashes to `c94563ba4883 4c66…74d9`\n- `imd-19093962` hashes to `c94563ba4883 0d17…2211`\n\nThe first 12 hex digits (48 bits) match exactly, the full digests differ, and the inputs are distinct. Python's `hashlib` and the command-line `sha256sum` tool gave the same digests.\n\n**How it was found:** `tools/find_collision.py` is a Python script that needs nothing beyond the standard library. It hashes `imd-0`, `imd-1`, … and stops when a 48-bit prefix repeats. That happened after 19,093,963 hashes, about 2^24.2, which is close to the expected cost of about 2^24.3. It took about 48 seconds, and running it again gives the same pair.\n\n**Not tested:** I couldn't run the SIMD verifier. The result assumes it reads \"48 bits MSB\" as the first 6 bytes of the digest, which is the standard reading. It also assumes it treats inputs without a `0x` prefix as UTF-8. The collision only applies to the 48-bit truncation and says nothing about full SHA-256.\n\nFiles:\n- **Committed:** `collision.json`, `tools/find_collision.py` and `README.md` (the question and its limits), in commit `009e367`.\n- **Left untracked as required:** `artifacts/report.md` (method and evidence, with facts, assumptions, uncertainty and open questions kept separate), plus a copy of `collision.json` in `artifacts/`. The repo's local git settings already ignore the `artifacts/` folder.\n\nGit had no author identity configured here, so I set your name and email for this one commit only, without changing the git config.","treeHash":"0251e8a5519da136ad0e7bb8a47d286e933becd7","usage":{"cachedInputTokens":183031,"inputTokens":16,"model":"claude-opus-5-5","outputTokens":4640,"runtime":"claude","turns":8,"wallClockMs":97936}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"05b86f26aac86cdd3e502dbe4e5b505301ae12ecc7f0b5ba1fbd62f69fb7a150","verifiedTreeHash":"0251e8a5519da136ad0e7bb8a47d286e933becd7","verifierVersion":"0.1.0+41305fb5"}]}