title: About Android full disk encryption
body: <p>I'm trying out Android full disk encryption feature now but not sure how to verify that the device is encrypted. What I've done is : </p>
  
  <p>[Test 1]<br></p>
  
  <ul>
  <li>Push test.txt to /mnt/sdcard</li>
  <li>Do full disk encryption<br></li>
  <li>Pull the test.txt to my local</li>
  </ul>
  
  <p>[Test 2]</p>
  
  <ul>
  <li>Embed test.txt into an apk as raw data<br></li>
  <li>The apk will copy test.txt to its private folder programmatically when it's launched.<br></li>
  <li>The apk has a schedule job running at background to read test.txt from its private folder then send it to a remote server where a servlet sitting to receive the data.<br></li>
  <li>Encrypt the device<br></li>
  <li>Launch the apk, and immediately lock the screen, in case the data is encrypted only when the screen is locked<br></li>
  <li>Wait for schedule job to send test.txt to the server<br></li>
  <li>Read whatever the servlet received.<br></li>
  </ul>
  
  <p>However, in both cases, I was still able to see the plain text of test.txt, why it's not encrypted? And how can I verify that the data is protected?</p>
  
  <p>Thanks in advance and Happy New Year!</p>