{"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":"77b9c366-fb6f-491a-bf61-4fa174a61a7c","kind":"skill:research-report","nodes":[{"acceptedSubmissionHash":"f18f442eca2d5b549ed5bf699455b969620ab3af3993b880ad6abf69740f7565","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":"77b9c366-fb6f-491a-bf61-4fa174a61a7c","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":"51382","feedbackHash":"1c051718319d8ce6055ac95d9194f389caac9a2246e549850bd59658f3aad5c5","nodeKey":"research_report","submissionHash":"f18f442eca2d5b549ed5bf699455b969620ab3af3993b880ad6abf69740f7565","tag1":"verification:structural","tag2":"acceptance-v2","value":1}],"site":null,"snapshotHash":"51ba4c27b00147cac29b460c764ab48b109579d37240b792a10c881af155d721","state":"completed","submissions":[{"artifacts":[{"bytes":2483,"hash":"ebb5de7b9f2f8bfc6b084bc088ca0fa7f0a97337901842ebaf67d14de3ea8223","mediaType":"text/markdown","name":"report","path":"artifacts/report.md"}],"attempt":1,"bundleHash":"74c6f8d9b4659663f5a4cd40baf396368e322380d0e92bfee60b7ec9f9e0621f","device":"85f29f4c09dba910","findings":[],"hash":"f18f442eca2d5b549ed5bf699455b969620ab3af3993b880ad6abf69740f7565","nodeId":"7a73f903-e56a-4bf3-8397-4fbe16a5e712","outcome":"completed","summary":"I found a real collision. The SHA-256 hashes of two different strings start with the same 48 bits, and I checked this with three separate SHA-256 implementations.\n\n**`collision.json`** (at the repository root):\n```json\n{\"algo\":\"sha256\",\"lambda\":24,\"inputA\":\"imd-28353144\",\"inputB\":\"imd-31301013\"}\n```\n\nBoth inputs are plain text strings with no trailing newline.\n\n| Input | SHA-256 |\n|---|---|\n| `imd-28353144` | **`10c5146afb50`**`8a551db9…1a932af5` |\n| `imd-31301013` | **`10c5146afb50`**`4c837e87…75c70950` |\n\nThe first 12 hex digits (48 bits) are the same. After that the hashes differ, so this only matches the shortened 48-bit hash, not full SHA-256.\n\n**How it was found and checked:**\n- **Search:** `tools/find_collision.c` is a small C program with its own SHA-256. It hashed `imd-0` through `imd-33554431` (2^25 strings), sorted the 48-bit prefixes and looked for a repeat. It took about 27 seconds and about 256 MB of memory. At that size you'd expect about 2 matching pairs, which is in line with the \"about 2^24\" cost in the task.\n- **Checks:** Python's `hashlib` and the `sha256sum` command both gave the same hashes as the C program. `tools/verify_collision.py` checks the JSON fields, that the two inputs differ, and that the first 48 bits match; it printed `OK`.\n\n**One open question:** I don't know exactly how the external verifier reads inputs. I used plain strings that don't start with `0x`, so they can only be read as text. If the verifier added a newline or anything else to the inputs, the hashes would change.\n\n**Files:**\n- **Committed:** `collision.json`, `tools/find_collision.c` and `tools/verify_collision.py`. The repo had no git name set, so the commit uses your email address with its local part as the name.\n- **Not committed:** `artifacts/report.md` (the report, which separates facts, inferences and open questions) and `artifacts/README.md`. Git already ignores `artifacts/` through `.git/info/exclude`.","treeHash":"8c9f4f4b78655fe7d687b473b09b65c522f90aa0","usage":{"cachedInputTokens":243086,"inputTokens":20,"model":"claude-opus-5-5","outputTokens":7598,"runtime":"claude","turns":11,"wallClockMs":101470}}],"verification":[{"checks":[],"detail":"paths and tree verified; no suite was run for this kind of work","evaluation":"structural","profile":"none","status":"accepted","submissionHash":"f18f442eca2d5b549ed5bf699455b969620ab3af3993b880ad6abf69740f7565","verifiedTreeHash":"8c9f4f4b78655fe7d687b473b09b65c522f90aa0","verifierVersion":"0.1.0+41305fb5"}]}