title: Comparing with previous passwords
body: <p>For security reasons, I need to force the user to change his password quite often and something I don't want is a password really close to the previous one, for obvious security reasons.</p>
  
  <p>But for security reason as well, I can't keep the real password in the DB (ie: I need to hash it or any other method).
  But I don't think comparing the hashes will help.</p>
  
  <p>Is there a way to compare 2 passwords in order to know if they are close to each other?</p>
  
  <p>Ex: password and password1 are too close to each other.</p>