[ Home ] [ Up ] [ Shift Substitution Cipher ] [ Breaking a Shift Substitution Cipher ] [ MonoAlphabetic Substitution Cipher ] [ The Playfair Cipher ] [ The Vigenère Cipher ] [ Factorial Utilities ] [ Simulating a Coin Toss ] [ Sieve of Eratosthenes ] [ Modular Arithmetic ] [ Message Digests ]

Breaking a Simple Shift Substitution Ciphertext

Below is an applet which allows you to break, from a specified plaintext, a ciphertext based on a simple shift substitution cipher.  Just click on its Start button to bring up the applet's frame:

Your browser does not have Java support. Please install the Java Plug-in.

Here's an image of what you should see:

If you don't see this, perhaps you don't have the Java Plug-in properly installed?

To break a ciphertext, type your ciphertext message in the upper text area, and click the Translate button.  26 candidate plaintexts will appear in the lower text area, with keys (shift values) identified.  From this list, you can visually pick out the most likely plaintext.