cryptoProhard

noteasy³ — Cubic Affine Cipher

spbctf

Task: Decrypt cubic affine cipher with custom 53-char alphabet. Solution: Known plaintext attack using flag format to build system of 4 equations, solve with Gaussian elimination mod 53, build decryption lookup table.

$ ls tags/ techniques/
modular_arithmeticaffine_ciphercubic_cipherpolynomial_cipher
known_plaintext_attackcubic_polynomial_ciphergaussian_elimination_mod
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