title: Best place to hide a key in the Windows Registry?
body: <p>My Delphi program has a built-in protection mechanism to check for banned license keys on the Internet and displays a message to the user if a blacklisted key is found.</p>
  
  <p>I'd like to store the blacklisted key in the registry, so if the user tries to re-enter it (and he/she is not connected to the Internet), it's not accepted.</p>
  
  <p>What is the best way to hide an obfuscated entry in the Windows registry?</p>
  
  <p>Thanks!</p>
  
  <hr>
  
  <p>Edit: You guys have some good answers there, but I feel like I need to expand the question.</p>
  
  <p>This is not mainstream software but a corporate one. Clients pre-pay one year and get a one-year license key for activation. The license key includes a machine ID and can't be used elsewhere.</p>
  
  <p>The problem is that some clients tend not to pay in time or they don't pay at all. Since I don't want to bother with shorter than one year license keys (too much administrative overhead) I need a way to disable their licenses till they pay.</p>
  
  <p>So the app now will connect to the Internet upon launch and check if their key is blacklisted. If it is, I need to disable access. In case they reinstall or block Internet access, I need to know if the key has been blacklisted.</p>
  
  <p>Thus, I'm thinking it would be best to hide it in the registry. My users are not tech-savy enough to use registry tools to monitor the registry, but if I put it under HKLM/Software/MyCompany/MyProgram, some of them might do find it. So I need a place where they can't find it afterwards that it had been created. (Noone will be expecting it!)</p>
  
  <p>Any ideas?</p>