title: How to allow only certain devices to access web site
body: <p>We are developing in-house web-based application for viewing data reports while targeting on smartphones and tablets. Our customer asked us for possibility that only certain devices could access the content. Hence we use technologies based on javascript/HTML5 we are no capable of reading unique ID like IMEI or device uuid. On the other hand side we could use server technologies like ASP, PHP to gain success.</p>
  
  <p>I have several ideas which dont lead to wanted result (one discussed here: <a href="https://stackoverflow.com/questions/18614188/persistent-client-side-web-storage">Persistent client-side web storage</a>).</p>
  
  <p>I wonder if you have any idea that allow only certain devices to access web site?</p>