Login authentication and WordPress

Hello,

I am wanting to host blogs on my website using one of the third-party-hosted blog solutions. I would like to require my readers to log in before leaving feedback. Additionally, I would like their user name to appear next to their feedback entry.

Here’s the catch – my site currently has its own user registration system. If a reader is logged into my website, I don’t want to force them to log in a second time in order to leave feedback on a blog. Likewise, if a reader logs in to leave feedback on a blog, I don’t want to make them log in again in order to leave feedback on my site.

The ideal situation would be this –

1) Whenever somebody logs into my site, I set some sort of cookie that is readable by the blog software. In the cookie, I will provide the blog software with any information it needs to know about the user. Thus, if a reader logs into my site and then starts reading a blog, they don’t need to log in again in order to leave feedback on the blog.
2) If a reader tries to leave feedback on a blog, but they have not already logged in to my site, the blog software should send the reader to the login/registration page on my site. This will allow them to log in to my site or set up a new account if need be.

Will WordPress let me do this?