end of the javascript functions

Mono-Alphabetic Substitution Cipher Tools

This page contains most of the tools that you need to write or break mono-alphabetic substitution ciphers. That is ciphers which use one alphabet only to substitute for the plaintext alphabet.
Paste the block of text that you want to manipulate into the "Plaintext" box. Then hit the relevant button. If you want to perform more than one operation then hit the "Move to Top" button.
Tooltips will appear if you hover over a control.
If you can read JavaScript then download the source and fiddle with it!

Plaintext





Manipulated text

Frequency Analysis Results

Substitution and Shift Ciphers



Random Substitution
Codeword

Affine a b

Substitution Cipher Guessing Tools

Plaintext letter=
Ciphertext letter=

Parallel Decoding

This tool tries all 26 simple shift ciphers against the first 25 letters of the ciphertext. This should enable you to spot a message that has been enciphered by a simple shift cipher.

last updated 12th September 2011