Security for Feature Hyperlinks

I was wondering if anyone had a requirement to secure feature hyperlinks - so that they can only be accessed via Geocortex Essentials rather than browsed to directly by anyone who knows the url.  

I had this functionality written for me by Latitude for the WebADF viewer and now need this rewritten so that it works with the REST elements and Silverlight.  The way this worked was to create a hyperlink proxy page which then called up the document (pdf, in my case) from a location on the server - which could not be browsed to directly.

With all of the discussion that goes on about site security and security of saved projects - I'm sure someone out there has a requirement to secure their hyperlinks as well.

Would anyone be willing to share the cost of this development with me?

Thanks

Caroline