Adobe Publish/AEM SSO

I need to find a way to either create a single sign-on (preferred) or a way to share/pass user credentials between an Adobe Publish site and an AEM site (same domain). Here's the specific scenario:

1. User goes to the Publish site and logs in
2. The user navigates to an AEM page that requires authentication (from the Publish site)
3. The AEM page is displayed without requiring a login

Or...

1. User goes to an AEM page that requires authentication
2. User isn't logged in, so s/he is routed to the Publish site for authentication
3. Once authenticated, the AEM page is displayed

Is this possible? I don't know what type of authentication Publish uses (LDAP?).

Thanks in advance,

John