title: Android security: how secure is the app private data?
body: <p>I have an application that stores confidential information in a file located in the application's private data folder.</p>
  
  <p>I would like to know how secure it is to do so.</p>
  
  <p>As far as I know on an android device other applications cannot access that file.</p>
  
  <p>Supposing:</p>
  
  <ul>
  <li>the device is not rooted </li>
  <li>there is a password protection on the lock screen</li>
  <li>a hacker has stolen that device and he is really forced to get that file</li>
  </ul>
  
  <p>What kind of tricks are there to get that file somehow? I mean:</p>
  
  <ul>
  <li>Is it possible to get the device rooted (in this scenario) and then get that file?</li>
  <li>Can the hacker physically take out the flash chip from the device and then he analyzes it using any tool. Does Android make any encryption preventing this way to happen?</li>
  <li>Other ways to get that file maybe?</li>
  </ul>
  
  <p>Is it possible at all to fully protect that file somehow? 
  Maybe the application could have an autostart service that monitors the rooted status. If the device gets rooted the service deletes the file immediately.</p>
  
  <p>Thank you!</p>