guideliness for securing ssl for fb

We really don't have instructions just for that. Depending on your server configuration, hosting settings, and numerous other settings, it can be easy, or hard, to enable an SSL cert just for specific areas of the site. Generally, enabling SSL for a whole site isn't a bad thing, but there are times when you may not want to do that.

You would likely need to contact your hosting provider to get ideas of how to do it on the subdomain. As for Joomla itself, they don't have an easy way to enable SSL on one page, but specifically disable it on others. Additionally, if the Page you plan to display has any links to other pages of your site, you're not going to be able to disable SSL across your site, as those pages would still need to be reachable through SSL.

Hope that makes sense, but feel free to let us know if you have more questions or need assistance.

Alex

The SSL certificate is only required if you're displaying your site within Facebook, either in a Page Tab or in a Canvas view. Our understanding is that any page that can be displayed within Facebook.com (by users navigating to them) will need SSL enabled. It's possible that it's only the main landing page that it's required on, but I haven't heard that, and there's no way to test since they haven't enforced that requirement yet.

For normal Facebook operations on your site (widget, authentication, etc), you do not need an SSL certificate.

Hope that explains,
Alex