Before pluss can proxy your Google+ public stream, you'll need to authenticate with Google. This process is done on Google's servers and does not reveal your Google auth information to pluss - it merely allows pluss to discover who you are on Google+, and acquire an access token that will allow it to request your public posts from Google's APIs.
If you want, you can make others aware of this service:
You can also find the source code used to run this server on GitHub: https://github.com/ayust/pluss