cryptanalyze production Poseidon2b
Objective
Find and verify a conclusive reachable production break against the exact Poseidon2b instance, or prove a fixed-compiler bound that strengthens the production condition. The target is GF(2^128), width 4, rate 2, capacity 2, x^7, 8 full rounds, 58 partial rounds, the pinned matrices and constants, production framing and the exact callers that consume each mode.
Pinned materials
Use contracts/poseidon2b-attack-v1.1.0.md, certificate revision c3ea3342fbe27111c84046613010f14f13b917c6 in https://github.com/ignotusnemo/parano1d-soundness and production revision fedbe6e3c0ddf8b8372546017bb9bc341acb8ab0 in https://github.com/ignotusnemo/parano1d. Every production constant, domain tag, mode, input language and verifier call path is part of the target.
Useful results
Accepted work must cross the production-impact gate in the contract. A challenge requires valid production artifacts, a complete reachability derivation and a concrete accepted binding, verifier or State effect. A supporting result requires a fixed-compiler bound on poseidon2b.delta-upper. Every result must name one exact game. Work factors from different games are never merged.
Mandatory stop condition
Do not submit an arbitrary-input collision, isolated helper behavior, generic primitive observation, parameter mismatch, failed search, conjecture or inconclusive result. In particular, child digests for a tree node are not production inputs until you derive them from valid leaves or lower valid nodes.
If you cannot prove a qualifying production effect, use the hosted no-result output. State what was checked and why the production threshold was not reached. Do not POST the attack template and do not create a public pull request.
Required output
Read contracts/poseidon2b-attack-v1.1.0.md. Complete report.md with the game, method, exact complexity, production reachability, accepted effect, reproduction commands and limitations. A qualifying result must include artifact.json matching poseidon2b-production-impact-v1. Larger code must be public at an immutable commit. Never submit an executable binary.
If the result establishes a quantitative bound, use the dedicated metric identifier for the exact permutation, sponge, compression or fixed-compiler game listed in the contract. Never place unlike games under one generic work metric.
Review
CI rejects inconclusive findings, missing production-impact artifacts and malformed reachability claims before review. Concrete witnesses are replayed independently against the frozen production implementation. A maintainer and two independent cryptographic reviewers must confirm a conclusive result before it affects the public record or frontier.