title: PHP protecting downloads
body: <p>I need a method to protect the download URL of a file from being seen by the downloader.</p>
  
  <p>The idea is that the user is given a download link after paying, but to stop them spreading the URL among their friends who haven't paid.</p>
  
  <p>What are some common solutions to this? Possibly changing file name?</p>
  
  <p>(I can do PHP, and mySql this post is for methods really)</p>