I would like to be able to give registering blog owners the ability to either elect to have a public or password protected blog.
A couple of plugIns exist that only enable registered logged in users to procede to blogs from http://www.yourmainsite.com. However, the login is global to the whole site and ALL daughter blogs. So if user1 logs in once, they have potential access to blog1.yourmainsite.com through blogn.yourmainsite.com.
If the name of the blog is not public then you can argue that user1 will not be able to find anon.yourmainsite.com. However this is not strong enough authenication , IMO.
If the admin of anon.yourmainsite.com adds user1 as an author or other role, a new field is recorded in the wp_usermeta table and could be quieried so that only user_id's associated to the specific blog can view the blog.
Can this be done through cookies or only with a database call? I am not a wp programmer and I was wondering if anyone would like to comment on whether this is the right approach or there is a better existing solution.