ADFGX
The ADFGX cipher is a variation of the ADFGVX cipher which involves a combination of Polybius Square and Columnar transposition, utilizing a key phrase to encrypt plaintext into a grid using ADFGX as coordinates.
Explanation
The ADFGX cipher is a variant of the ADFGVX cipher. Both the ADFGX and ADFGVX ciphers are similar in structure and operation, but the ADFGX cipher uses a 5x5 grid instead of a 6x6 grid.
A 5x5 grid, usually called the Polybius square, is created. The rows and columns are labeled with the letters A, D, F, G, and X.
Each letter of the plaintext is replaced with its corresponding pair of letters from the grid. For example, if the letter 'C' corresponds to 'DG', then 'C' is replaced with 'DG' in the ciphertext.
The resulting fractionated ciphertext is then encrypted using a keyword or keyphrase, similar to the ADFGVX cipher. This typically involves a transposition step, such as columnar transposition, to rearrange the letters of the fractionated ciphertext.
The transposed ciphertext is then arranged into a single line to produce the final encrypted message.
Like the ADFGVX cipher, the ADFGX cipher combines both fractionation and transposition to enhance security. The fractionation step increases the complexity of the cipher, making it resistant to frequency analysis, while the transposition step further scrambles the ciphertext.
Overall, the ADFGX cipher is a historically significant encryption technique that demonstrates the use of both fractionation and transposition in cryptography.
Facts
It was used extensively by the German Army during World War I, but it was eventually broken by French cryptanalyst Georges Painvin in 1918.
It was considered one of the most secure ciphers of its time.
It was used in part because it is able to be transmitted quickly using Morse code.