ADFGVX Cipher
| A | D | F | G | V | X | |
|---|---|---|---|---|---|---|
| A | S | E | C | R | T | A |
| D | B | D | F | G | H | I |
| F | J | K | L | M | N | O |
| G | P | Q | U | V | W | X |
| V | Y | Z | 0 | 1 | 2 | 3 |
| X | 4 | 5 | 6 | 7 | 8 | 9 |
AFVVXXXVXAAAVAVFVFGVDGFAAAVF
Encode through a square then a transposition
ADFGVX was a German field cipher from World War I. Each plaintext symbol is replaced by its row and column labels in the keyed square — fractionation — and the resulting ADFGVX letters are then scrambled by a keyword columnar transposition. Splitting each symbol across two stages is what made the cipher hard to break in 1918.
When to use this tool
Reach for the ADFGVX cipher when a CTF challenge, puzzle, escape room, or cryptography lesson involves the famous World War I German field cipher. Introduced in 1918, it pairs a Polybius-style 6×6 fractionation square — holding all 26 letters and 10 digits — with a keyword columnar transposition, so a single substitution square is no longer enough to read the message. It sits naturally beside the Bifid, Trifid, Polybius Square, and Columnar Transposition tools, rounding out the fractionation-plus-transposition family of classical ciphers here.
Privacy and limitations
Everything runs locally in your browser; nothing is sent anywhere. This is a classical cipher, not real encryption — both known keywords make it straightforward to reverse. The square keyword seeds a mixed 6×6 square of A–Z and 0–9 (no I/J merge), and the transposition keyword needs at least two letters or the output is held back with an inline warning. Encoding is case-insensitive and drops every character outside A–Z and 0–9 before fractionating, so spaces, punctuation, and case are not preserved — a decode returns uppercase letters and digits only rather than your exact input. Use the encode/decode toggle to switch directions, since the transform is not self-inverse.