How to bind a link to a site and Nginx server?

Question

Nginx

There is a link to download "Direct" _site_/file/live.mp3 It is
necessary that only on the site they can listen, but get up in winamp and listen there.
You can make a link under md5, but this is not an option, authorization. also doesn't fit.
Maybe there is a way to come up with something with cookies? For example, check whether he is listening to the site or not? It is necessary that the nginx hotlink works, it does not allow you to insert it into other sites, but with winamp, VLC, things are bad, even if the forest does not grow there.