title: Persistent client-side web storage
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. My idea consists in making random ID (very simple) and storing (not simple) such an ID on server and device using:</p>
  
  <p>localStorage,
  cookies,
  html5 file api,
  webSQL,
  indexedDB
  wrapped in <a href="http://amplifyjs.com/api/store/" rel="nofollow">http://amplifyjs.com/api/store/</a>
  or <a href="http://samy.pl/evercookie/" rel="nofollow">http://samy.pl/evercookie/</a></p>
  
  <p>The <strong>problem</strong> is that abovementioned techniques are <strong>not</strong> quite <strong>persistent</strong>. They are vulnerable to cookie and/or cache cleaning.</p>
  
  <p>Can we make such an ID "more" permanent or could You find any other workaround to allow connect only certain devices to the site?</p>