ASP.NET MVC: The right way to propagate query parameter through all ActionLinks

Question

In my application, key query string parameter can be used to grant access to certain actions/views.
Now I want all ActionLinks and Forms to automatically in

Answer 1

How about adding the key to route values.

{controller}/{action}/{key}

Whenever a url contains a querystring with key=somevalue, the url will look like

Home/Index/somevalue,

Now all the action links and relative urls also will include this by default.