title: How to store a Secret Key for Encryption
body: <p>I am building an authentication system in which some information is being stored encrypted so that it can't be human readable. Because it is encrypted, I need to use the <code>generateSecretKey()</code> function (as I'm not using the CFMX_COMPAT method). I am nervous of just creating this when a user is registered in the system and using it for all time and so I thought about creating a new one every time the user logs in, but wasn't sure if that is really necessary. I am already calling a method to update the users login timestamp on each login so adding a new secret key isn't bad, but I wanted to make sure that I didn't go overboard, so my question is this:</p>
  
  <blockquote>
    <p>When generating secret keys for users to encrypt information is it best to create a new one every time they login or just create one on registration and use it for all time?</p>
  </blockquote>