Please note that you need the latest version of Node.js and Ruby.
To create a key you must have node.js installed to run Java Script.
Navigate to the lib folder and make sure you run the following command:
node key.js
This will now write an encryption key to generated.key.
Now, you should place the file you wish to encrypt in the lib folder.
After that, you run:
ruby enc.ru
Following the instructions, you should now have an encrypted file.
Repeat that step again to decrypt it.