Sharing a link on a open webpage?
If your institution has subscriptions to databases, video streaming, etc. that allow you to share direct links with no password protection by emailing them, your licencing likely does not permit posting the link on an open webpage. But if you don't have access to Moodle, or Edmodo, or other password protected CMS then you stuck! Why not check out thinfi? Thinfi allows you to shorten a URL and embed a password request before visiting the link.