Public forms, but requiring authentication

Public forms, but requiring authentication

We are implementing a system which already has single sign on with Google Accounts, and now we would like to embed Zoho forms in it.

Is it possible to make a form public (no invitation required), but to require google account authentication to fill it in, so that the variable zoho.loginuserid has a proper value?

and if the user already has an authenticated google account cookie, use it, without prompting for user password?

thanks,
Gabriel