{"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":"813aac02-c29f-4bfd-9a0a-c4124a5fbf8d","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"1f167e63bf333821ce64b37d984fa8a9aeb1bd418f8f27ca4fd4a4feef97297a","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":"813aac02-c29f-4bfd-9a0a-c4124a5fbf8d","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":"51168","feedbackHash":"532e2c2a781928511776031601a39919d74722b68376eb7ab372c5a73610273c","nodeKey":"research_report","submissionHash":"1f167e63bf333821ce64b37d984fa8a9aeb1bd418f8f27ca4fd4a4feef97297a","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"8cf0f38dc989fcb0980f89e840d58a8cc1f3cb380251741889248cedb2fdf045","state":"completed","submissions":[{"artifacts":[{"bytes":4492,"hash":"f1a853e815f21998ef3b6aca70553a530e85623d146630d117fed45be3b339e1","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"49562b9dc667b687646502d6bfe4fe21f7d00e30d824d838d54574200b62ee1c","device":"6208734cdf5317a1","findings":[],"hash":"1f167e63bf333821ce64b37d984fa8a9aeb1bd418f8f27ca4fd4a4feef97297a","nodeId":"d39f02aa-9bad-4ce5-814d-779d8d7fda3a","outcome":"completed","summary":"I found a real collision: two different 6-byte inputs whose SHA-256 digests share the same first 48 bits. It's in `collision.json`:\n\n```json\n{\"algo\": \"sha256\", \"lambda\": 24, \"inputA\": \"0xcfc944ab2e1c\", \"inputB\": \"0x408f1b45687d\"}\n```\n\n| Input (hex bytes) | SHA-256 |\n|---|---|\n| `cfc944ab2e1c` | `2417e9dafc1a`1181a2f7813ee65ae982e166e70b23fa437449f214f9d2551ce6 |\n| `408f1b45687d` | `2417e9dafc1a`97b1c28da5d74d80aeaa64600a79cb62fd74c77787f26b34de2f |\n\n**How I checked it:**\n- The search script checks its own result before writing the file.\n- A separate checker script (`tools/verify_collision.py`) re-reads `collision.json` and recomputes both hashes. It confirms both truncate to `2417e9dafc1a`.\n- The standard `sha256sum` tool gives the same full digests, byte for byte.\n- The checker rejected two bad files I gave it: one with inputB changed by one bit, and one with identical inputs.\n\n**How it was found:** `tools/rho_collision.py` uses only the Python standard library. It took 17 seconds and about 2^25.6 hash evaluations, which is what you'd expect for a 48-bit target (roughly 2^24 times a small constant). It needs almost no memory and gives the same answer every run.\n\n**One assumption is unconfirmed:** I wrote the inputs in the `0x` hex form the task allows, meaning they stand for 6 raw bytes. If the outside checker hashed the 14-character text `\"0xcfc944ab2e1c\"` instead, the pair would not collide. I couldn't see that checker, so I've flagged this in the README and the report.\n\n**Delivered:**\n- **Committed** (`4b37f63`): `collision.json`, `README.md`, and the two scripts in `tools/`.\n- **Not committed:** `artifacts/report.md`, as you asked, for the daemon to upload. It sets out the evidence, the reasoning, and the open questions separately. Its three literature citations come from my memory; I didn't look them up again during this task. The collision itself doesn't depend on them.\n\nThis says nothing about full SHA-256. Finding a collision on a 48-bit cutoff at this cost is expected for any hash function, not a weakness.","treeHash":"8c5dee42affbf0aa9746c43f81e6da37c22745b3","usage":{"cachedInputTokens":186237,"inputTokens":16,"model":"claude-opus-5-5","outputTokens":8395,"runtime":"claude","turns":8,"wallClockMs":104693}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"1f167e63bf333821ce64b37d984fa8a9aeb1bd418f8f27ca4fd4a4feef97297a","verifiedTreeHash":"8c5dee42affbf0aa9746c43f81e6da37c22745b3","verifierVersion":"0.1.0+41305fb5"}]}