{"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":"0367527e-e18e-42b0-8edc-bb843bad9df6","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"337e36658e4e916b70dff7c4aa06342441381d824ab0ed52725f7fdf396faf9a","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":"0367527e-e18e-42b0-8edc-bb843bad9df6","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":"51875","feedbackHash":"ec7a954670ed93872e6e0a2b04bd679f7c24b1a9801b1fede4b08c2d1fa3e9f4","nodeKey":"research_report","submissionHash":"337e36658e4e916b70dff7c4aa06342441381d824ab0ed52725f7fdf396faf9a","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"e43e1497d24b07fa35eb4ba7880c027ffbc78fa22e0423808bf623ea383180ba","state":"completed","submissions":[{"artifacts":[{"bytes":10589,"hash":"d0488d0f6d69feddf9d2857845ce030fd2868072f65d68dad445c25964c10fa1","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"6cc8a2e8a9a1cbe01084755ae2c1c61b978efb9e6a3a8cd5f97a475ffd17c295","device":"672c29f92850efe0","findings":[],"hash":"337e36658e4e916b70dff7c4aa06342441381d824ab0ed52725f7fdf396faf9a","nodeId":"1a92a165-2339-4e57-8bc6-da76aa4f8324","outcome":"completed","summary":"Done. Collision found, verified, and documented.\n\n## Answer\n\n```json\n{\"algo\":\"sha256\",\"lambda\":24,\"inputA\":\"0x19688697e11d\",\"inputB\":\"0x750293ffd1bf\"}\n```\n\nBoth digests begin `9378a7ecb4cb`:\n- `sha256(0x19688697e11d)` = `9378a7ecb4cb`​`31da3757efee0802c863c66525359462f68cb78e87c8dcb42793`\n- `sha256(0x750293ffd1bf)` = `9378a7ecb4cb`​`2655c297afe1c9661fbbc59d5629aa148699407b5674e1a38aff`\n\n## Method\n\nPollard's rho with Brent's cycle detection over `f(x) = sha256(x)[:6]`. The environment had no C compiler and no numpy, and a birthday table needs ~21M stored digests (multi-GB in pure Python), so I traded ~2.2× more hash evaluations for O(1) memory. Found in **35.7 s / 37.6M evaluations** (= 2.24 × 2²⁴) single-threaded.\n\n## Evidence\n\n- **Logic validated first** at 16/24/32-bit truncation × 8 seeds — 24/24 trials produced re-verified collisions, so the 48-bit run wasn't the code's first output.\n- **Four SHA-256 implementations agree** on both digests: Python `hashlib`, `openssl dgst` 3.0.13, GNU coreutils `sha256sum` 9.4, and a from-scratch FIPS 180-4 implementation self-tested against NIST vectors. The last one matters because `hashlib` and `openssl` share a backend on this host and aren't mutually independent.\n- **Deterministic**: re-running the search from its recorded seed reproduced a byte-identical `collision.json` (`cmp`-confirmed).\n- `tools/verify_collision.py collision.json` → **8/8 PASS**, exit 0.\n\nIncidental finding: the digests actually agree on 51 leading bits, not 48.\n\n## Main caveat\n\nThe one unconfirmed assumption is encoding: I read `0x19688697e11d` as six raw bytes. SIMD's decoder source wasn't available in this workspace, so that's an inference from the format offering a hex option — flagged as U1 in the report, with a UTF-8 variant as the fallback if hex is rejected.\n\n## Files\n\n- `collision.json`, `artifacts/report.md` — named outputs, left untracked\n- `tools/find_collision.py`, `tools/verify_collision.py`, `README.md` — committed (2 commits, stdlib only, no dependencies to vendor)\n\nThe report separates facts (F1–F10, each from a command run here), inferences (I1–I4), uncertainty (U1–U5), and four open questions. One correction to the task's framing worth noting: the rho cycle length (7,807,993) is also conventionally called λ, unrelated to the task's λ=24 truncation parameter — I disambiguated it in the report rather than letting the collision stand.","treeHash":"42555fdef2cdba900617edc98551e7ca73b24937","usage":{"cachedInputTokens":578260,"inputTokens":34,"model":"claude-opus-5","outputTokens":23665,"runtime":"claude","turns":17,"wallClockMs":374792}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"337e36658e4e916b70dff7c4aa06342441381d824ab0ed52725f7fdf396faf9a","verifiedTreeHash":"42555fdef2cdba900617edc98551e7ca73b24937","verifierVersion":"0.1.0+41305fb5"}]}