You can use the following site to encrypt your own code and generate a CloudAuthX external call to place in your plugin!
You will need to make sure your users have the latest version of Clockwork and the CloudAuthX .dll to run your encrypted code! They can get the latest version by re-downloading from the Store or the Git repository. A special update to Clockwork and the .dll was made for this to be possible.
http://authx.cloudsixteen.com/
This will only work for server-side code. Client-side code cannot be encrypted.