This is a Scala implementation of the Playfair cipher.
You can run Playfair from the command line by executing scala -classpath bin Playfair. A file chooser will pop up to allow to to select a file to encode or decode.
The first line of the file defines the action that should be performed and the keyword that should be used when performing that action. Options are:
encipher <keyword>
decipher <keyword>
A Playfair cipher will be generated based on <keyword>, and the cipher will be applied to the remainder of the selected file. encipher.txt is a sample file for encoding a message, and decipher.txt is a sample file for decoding an encoded message. Enciphered messages are grouped into quintuples for output. Deciphered messages contain no whitespace.