Search for a tool

Tool to decrypt/encrypt with ADFGVX. ADFGVX is a German encryption system invented by Fritz Nebel in 1917. ADFGVX uses a 6x6 square grid to replace the plaintext by pairs of letters among A,D,F,G,V,X and then this ciphertext get a permutation of its letters (transposition).

Results

Tag(s) : Cryptography, Substitution Cipher, Transposition Cipher

dCode and you

dCode is free and its tools are a valuable help in games, puzzles and problems to solve every day!
You have a problem, an idea for a project, a specific need and dCode can not (yet) help you? You need custom development? Contact-me!

Team dCode read all messages and answer them if you leave an email (not published). It is thanks to you that dCode has the best ADFGVX Cipher tool. Thank you.

### Without knowing the grid

Tool to decrypt/encrypt with ADFGVX. ADFGVX is a German encryption system invented by Fritz Nebel in 1917. ADFGVX uses a 6x6 square grid to replace the plaintext by pairs of letters among A,D,F,G,V,X and then this ciphertext get a permutation of its letters (transposition).

### How to encrypt using ADFGVX cipher

The encryption uses a 6x6 square grid of 36 distinct characters (usually the latin alphabet and the 10 figures).

Lines and columns named, from top to bottom and from left to right, by the letters A, D, F, G, V and X

Example: A grid filled with AZERTYUIOPQSDFGHJKLMWXCVBN0123456789:

A D F G V X \ A Z E R T Y U I O P Q S D F G H J K L M W X C V B N 0 1 2 3 4 5 6 7 8 9

Each character of the plain text must exist in the grid in order to be localized by a coordinate (line, column).

Example: A = (A,A), B = (V,A), C = (G,V), D = (F,A) etc.

By replacing each letter of the message with the pair of coordinates, the intermediate ciphered message is then a simple substitution with bigrams.

Example: DCODE becomes FA,GV,DF,FA,AF.

This message will get another encryption by columnar transposition. The transposition uses a permutation key, usually based on a keyword. One can find it by rearranging the letters in alphabetic order.

Example: KEY => K(1),E(2),Y(3) => E(2),K(1),Y(3) => 2,1,3

The message is written in a table whose width is the key size. Empty box are filled with X (or another letter).

Example:

 F A G V D F F A A F X X

Columns are rearranged such as the permutation key.

Example:

 A F G D V F A F A X F X
Here column 1 (K) switches with column 2 (E).

The final ciphertext is created by reading the letters of the table by columns starting from top to bottom and from left to right.

### How to decrypt ADFGVX cipher

The ADFGVX decryption process requires a key and a grid.

Example: The cipher text is AD,AX,FV,FF,GF,AX and the keyword is KEY (that correspond to permutation K(1),E(2),Y(3) => E(2),K(1),Y(3) => 2,1,3)

The ciphered message is then written from top to bottom and from left to right in a table with $$n$$ columns where $$n$$ is the length of the key. Columns are named according to the letters of the key, rearranged in alphabetic order.

Example:

 A F G D V F A F A X F X

The table gets a permutation of its columns according to the permutation key in order to get back the original order of the keyword's letters.

Example:

 F A G V D F F A A F X X

Reading the table by row gives the intermediate message.

Example: FAGVDFFAAFXX.

For each bigrams, replace it with the corresponding letter with coordinates (line, column) in the grid to get the plain text message.

Example:

A D F G V X \ A Z E R T Y U I O P Q S D F G H J K L M W X C V B N 0 1 2 3 4 5 6 7 8 9

Example: FA = line F, column A = D then GV = C, etc. The original plain text is DCODE.

### How to recognize an ADFGVX ciphertext?

The ciphertext must contain only 6 distinct characters: A, D, F, G, V and X.

(Optional) The ciphered message must have number of character divisible by the permutation length.

### How to recognize a non-permuted text?

If the ciphertext hasn't be permuted, the text is a simple bigrammic substitution. After a replacement by a random alphabet, the text should have an index of coincidence similar to the one of the plaintext language.

### How to decipher ADFGVX without key for permutation?

One can crack ADFGVX and find the permutation order without knowing the key by bruteforcing all possible permutation. Use the Permutation Brute-force button.

### How to decipher ADFGVX without grid

One can crack ADFGVX and find the substitution grid by making a simple alphanumeric replacement of the bigrams resulting from the permutations. Use dCode's tool for mono-alphabetic substitution.

### How to decipher ADFGVX without key nor grid?

One can crack ADFGVX without the key nor the grid by finding first the permutation (see below) and then do an alphabetical substitution.

The letters A, D, F, G, V and X have been selected because their equivalent in morse code are very distinguishable, his prevent transmission error by radio

### When ADFGVX have been used?

ADFGVX cipher have been introduces at the end of the First World War (from 1917). He have been used on the 5th of March 1918 during the german attack of Paris, it was using the letters A, D, F, G and X only.

### What is the GEDEFU 18?

GEDEFU 18 for GEheimschrift DEr FUnker 18, which can be translated in radio-operators' cipher 18 is the old name of ADFGVX cipher.

ADFGX is an ancestor of ADFGVX, a variant using a 5x5 square, on the base of the Polybius square cipher.

### Who did crack ADFGVX cipher?

The crack is attributed to George-Jean Painvin.

### When ADFGVX have been cracked?

George-Jean Painvin deciphered a first message in June 1918.