Sébastien Georget wrote at 2003-9-5 16:51 +0200:

does anybody know if there is a way to provide a cross-site authentication between different Zope instances ?

We use session based authentication, maintain the session data in a database shared by all participating sites and exchange the session key (via URL's). In a cooperation with a partner we get a login request (via encrypted URL request), assign a session and later use the session key for authentication. Dieter