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So I've read up on SSO, and it seems pretty straight forward, however one thing I'm unsure on is being able to use SSO on multiple domains.

I've come up with the conclusion that it will probably be required that my Sessions are stored on the authentication's server's database, however I'm not sure if this would work.

Reason:

When you visit a website, you're assigned a UUID which acts as the Session, this UUID is both stored as a cookie on your browser and on the web-server in order to validate the user.

My overall question is:

Would it be possible to have the same UUID assigned to the user cross-domains?

If I'm thinking too much in-depth about this, and I maybe going a more complicated route, could someone please point me in the right direction? I'd appreciate it.

Thanks!