You can choose to let your users log in by using their social networks credentials. Here is how it looks like from the user perspective:
When the user clicks on the social network of their choice they will be redirected to the social network login confirmation page and back to the landing page, you provided when creating the portal.
Integrate the social network registration in your portal template
When uploading the portal, it will be parsed to look for an HTML element with the source property set to the registering method. It must be in a form HTML element. The form element itself can have no properties, they will be added automatically when uploading the template. It is advised to do it on the submit element like this:
<submit type="hidden" name="source" value="facebook">
The rest of the authentication process will be done on the backend making social network registration a no-hassle process for you.
The following authentication providers can be used: