Caesar Shift Cipher will allow the Encryption And Decryption of data using any of the twenty-five possible monoalphabetic shift-substitution ciphers. The Shift value button permits the setting of the amount of shift (one to twenty five) and this must be set before you can encrypt or decrypt data.
The first cipher to be used for serious purposes, Julius created the original which encrypted each letter by substituting it with the letter three characters along in the alphabet. In this implementation, you may of course choose any degree of shift you wish. In more Modern times, this cipher has been used to encrypt messages on Usenet and other areas of the Internet - ROT13 is a Caesar Shift Cipher with a shift value of thirteen.
Using the Open Plaintext or Open Ciphertext buttons on the tool bar, you may open a standard text (.txt) file or Caesar Shift Cipher text (.csc) 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 Caesar Shift Cipher text (.csc) file, as appropriate.
There is no file size limit in Caesar Shift Cipher although your operating system and memory configuration may impose such limits. Menu options include functions similar to the toolbar, along with various help options.