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ADFGVX fractionates each letter into two symbols and then shuffles them with a columnar transposition, the combination that made it Germany's toughest field cipher of 1918. This guide runs the modern automated attack: recover the transposition with the index of coincidence, then solve the substitution with quadgrams, and read a 330-letter message back out.
14 min read
Learn about ADFGVX, the German WWI field cipher that combined Polybius-square fractionation with columnar transposition. It was considered so strong that French cryptanalyst Georges Painvin needed weeks to break a message that helped stop a 1918 offensive.
14 min read
Columnar transposition doesn't hide letters. It just rearranges them, so frequency analysis finds nothing wrong. Learn the attack that actually works: brute-forcing every column order for each candidate key length, scored by common English substrings.
18 min read
Learn about the columnar transposition cipher, a classic cipher that scrambles the order of letters instead of replacing them. Learn why combining it with substitution led to some of the toughest hand ciphers ever used.
13 min read
