{"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":"3c74d720-23cb-48a9-9ec4-6cf75dacfdd6","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"99c4a67081da94268a33a06829efffbebfce7d0be644c3490c3885e6301a0902","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":"3c74d720-23cb-48a9-9ec4-6cf75dacfdd6","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":"51883","feedbackHash":"3ca12e5882921629429dd773223d11bb8b6d460f826c0190eb85e3e304fa60a0","nodeKey":"research_report","submissionHash":"99c4a67081da94268a33a06829efffbebfce7d0be644c3490c3885e6301a0902","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"4641a93dfaa5f3f56091c33bc56625eaf148005daff0889ca20a15434939bbf9","state":"completed","submissions":[{"artifacts":[{"bytes":14225,"hash":"696ecc34c49076dce44a77ee99b11ccd42ddb48239795506ea020837f9367034","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"145c64eff8f099984dde375af5d612aff9ced14a3ec8a109ddeb37cf34e95b7a","device":"707624586655cf74","findings":[],"hash":"99c4a67081da94268a33a06829efffbebfce7d0be644c3490c3885e6301a0902","nodeId":"0dbb7098-8dde-4b49-91a5-f68131f02738","outcome":"completed","summary":"Done. Found and verified the collision.\n\n## Result\n\n```json\n{\"algo\": \"sha256\", \"lambda\": 24, \"inputA\": \"simd-collision-sha256-lambda24-n21149750\", \"inputB\": \"simd-collision-sha256-lambda24-n23077827\"}\n```\n\n```\nsha256(A) = fd7170e0e000 420d6e61cc5ba1838327a6bd9dc57de8f30cde811214b59a69ee\nsha256(B) = fd7170e0e000 1e50098e64f70ab42ffe03db0058cf23a9b21e2a3196e398d8c6\n            ^^^^^^^^^^^^ 48 shared bits; full digests differ\n```\n\nBirthday search over a fixed message family, 23,077,828 SHA-256 evaluations (2^24.46, 1.17× the 2^24.24 median) in 57 s on one core. Pure Python stdlib — no compiler or `pip` was available, and nothing needed vendoring, so the pipeline runs offline from the committed files.\n\n## Verification\n\nFive implementations recompute both digests and agree: Python `hashlib`, Node `node:crypto`, `openssl dgst`, coreutils `sha256sum`, and a from-scratch FIPS 180-4 implementation. All are checked against published NIST vectors (including the million-`a` Appendix B.3 case). A tampered input makes every verifier exit non-zero, and the search reproduces `collision.json` byte-for-byte across three runs.\n\nTwo things worth flagging, both recorded in the report:\n\n- **`ldd` showed `sha256sum` links the same `libcrypto.so.3` as Python**, so the obvious four tools collapse to one OpenSSL code base. That's why I added `src/sha256_reference.py` — written only from the spec, no OpenSSL — giving three genuinely independent code bases rather than an inflated count of five.\n- **A draft compared a 22-bit tag instead of the full truncated digest** and reported a false positive on the first scaled-down run (`40d4d4` vs `40f4d4`): linear probing can place an entry in a slot that isn't its own base. Caught before the real search; it's the reason every result is confirmed by recomputation rather than the search's own bookkeeping.\n\n## Files\n\nDeliverables (untracked, per instructions): `collision.json`, `artifacts/report.md`, plus an identical copy at `artifacts/collision.json`. Source is committed in `b897ada`: the search, four verifier scripts, the reference implementation, and `run.sh` to reproduce end-to-end.\n\nThe report separates facts (F1–F8, each naming the command that produced it) from inferences (I1–I3), uncertainty, and open questions. The main thing it **cannot** establish is how the grader parses the input strings — I chose UTF-8 with non-hex characters (`s`, `l`, `m`, `n`, `-`) and no `0x` prefix, so the strings can't be silently misread as hex; the `0x`-hex form also verifies here, but the grader's actual parsing was not observable from this environment.","treeHash":"51571f538d04fd6b6ee35815c116aa58ec3b5848","usage":{"cachedInputTokens":2986373,"inputTokens":102,"model":"claude-opus-5","outputTokens":50561,"runtime":"claude","turns":51,"wallClockMs":853302}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"99c4a67081da94268a33a06829efffbebfce7d0be644c3490c3885e6301a0902","verifiedTreeHash":"51571f538d04fd6b6ee35815c116aa58ec3b5848","verifierVersion":"0.1.0+41305fb5"}]}