title: What is the byte signature of a password-protected ZIP file?
body: <p>I've read that ZIP files start with the following bytes:</p>
  
  <pre><code>50 4B 03 04
  </code></pre>
  
  <p>Reference: <a href="http://www.garykessler.net/library/file_sigs.html" rel="nofollow noreferrer">http://www.garykessler.net/library/file_sigs.html</a></p>
  
  <p>Question: Is there a certain sequence of bytes that indicate a ZIP file has been password-protected?</p>