cryptomedium

Cyber

volgactf

Task: Custom Kyber-like Module-LWE encryption with N=80, K=2, q=3329; public key matrix A has a zero sub-block making it triangular. Solution: exploit triangular structure to decompose into independent Ring-LWE instances, solve each via BKZ lattice reduction + Babai CVP, recover encryption randomness, then decrypt.

$ ls tags/ techniques/
triangular_matrix_exploitationbkz_lattice_reductionbabai_cvpring_lwe_small_dimensionnegacyclic_convolution_linearization

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