Substitution Cipher will allow the encryption and decryption of data using monoaphabetic substitution. The Key button permits setting of the user-defined cipher alphabet and this must be set before you can encrypt or decrypt data.
The implementation of this cipher allows you to define any cipher alphabet you wish, provided it contains each of the twenty six letters, with no spaces or non-alphabetic characters.
Using the Open Plaintext or Open Ciphertext buttons on the tool bar, you may open a standard text (.txt) file or Substitution Cipher text (.stc) file for processing. The size of the file in bytes, and the file name and path, are displayed on the status bar. Using the Close Plaintext or Close Ciphertext buttons, the data stores and displays are cleared.
The Encrypt and Decrypt buttons will allow processing of the source data after first stripping away any spaces, punctuation and numbers. Please note that you must load the source data into the correct pane. If you are encrypting, load the plaintext source into the upper pane. If decrypting, load the ciphertext source into the lower pane.
Print buttons are available to allow the printing of the contents of both the Plain and Cipher text panes.
Using the Save Plaintext or Save Ciphertext buttons on the tool bar, you may save pane contents to a standard text (.txt) file or Substitution Cipher text (.stc) file, as appropriate.