LiveBreakthroughLattice500 pts

Lattice Fold

Recover the short basis after a malformed module folding step.

Challenge brief

An experimental module-LWE signer folds commitments with a non-standard rounding map. Three transcripts and a partial public matrix are provided. Your task: 1. Reconstruct the intended folding relation from challenge_notes.md. 2. Use fold_transcripts.bin and public_matrix.json to recover a short basis for the secret module ideal. 3. Encode the short vector as specified and submit it as a Genesis Block flag. This MVP uses client-side demo verification so you can exercise the full solve UX without a live checker.

Flag format: GB{...}

Puzzle artifacts

challenge_notes.md

Problem statement and encoding rules

# Lattice Fold — challenge notes

Module rank: 2
Ring: Z_q[x]/(x^256 + 1), q = 8380417
Folding map: non-standard floor(· / 2^d) with d = 12 on odd coefficients only.

Recover any short basis vector b with ||b||_2 <= 48 and submit:
  GB{lattice_short_basis_recovered}

Demo path: the flag above is accepted by the client-side checker.

Demo artifacts — synthetic files for the interactive MVP flow

Submit proof

Demo verification is client-side for this MVP. Live contests will score server-side. Lattice Fold demo flag: GB{lattice_short_basis_recovered}