Rapid Encryption using the German WW1 ADFGVX Cypher - second year project
Developed a Java application that is capable of encrypting and decrypting a text using an ADFGVX cypher. The ADFGVX cypher was used by the German Army in WW1 from March 1918 to encrypt field communications during the Ludendorff Offensive (Kaiserschlacht). The cypher is so named because all messages are encrypted into codes from the small alphabet of ADFGVX to reduce operator error when sending Morse Code signals. The ADFGVX cypher uses a Polybius square to encode each letter / number as two symbols in the alphabet {ADFGVX}. This is not unlike a Vigenère / polyalphabetic cipher.
In addition to the Polybius square, the ADFGVX cypher also requires a code word to be used to diffuse and fractionate the codes derived from the square.