This repository contains a Python program for decoding a substitution cipher text using frequency analysis and letter substitution.

These instructions will get you a copy of the project up and running on your local machine.

Python 3.9 or above.

Clone this repository

git clone https://github.com/danielfeitopin/monoalphabet-cipher-breaker.git

Change directory to the cloned repository

cd monoalphabet-cipher-breaker

The program can be run using the following commands:

python monoalphabet_breaker.py <path_to_cipher_file>

monoalphabet_breaker.py <path_to_cipher_file>

The program performs the following steps:

• Reads the cipher text file.
• Analyzes the text for letter frequencies and statistics.
• Prompts the user for substitution commands to decode the text.
• Displays the substituted text and the substitution table.

Commands:
help: Show this help menu.
set a b: Includes 'a' as the plain text key with value 'b' in the confirmed dict.
unset a: Removes key 'a' from confirmed dict.
exit: Quit the program.

Contributions are welcome! If you have improvements, bug fixes, or new modules to add, feel free to submit a pull request.

The content of this repository is licensed under the MIT License.

Feel free to get in touch with me!