cryptomedium

Square Simple — Polybius Square

spbctf

Task: Decode ciphertext using a 5x5 Polybius square with hint "dream == trunk". Solution: Coordinate reflection cipher where letter at (r,c) maps to (4-r, 4-c).

$ ls tags/ techniques/
substitution_ciphercoordinate_cipherpolybius_squareclassic_cipher
polybius_coordinate_reflection
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