Plugin for Google Groups to Authentiate per page

I am going to be working with a client who want to have three types of pages for their WordPress site. 1) Public pages with no authentication needed, 2) Private pages based on membership in Google Group A and 3) Private pages based on membership in Google Group B.

Are there any plugins that would allow this functionality already in existence? If there are, can you see a page that is permissioned for both groups or does it only allow one group per page which would require you to be a member of both groups?

~M