title: Finding whether two users have the same password
body: <p>I am making a web game in Python/Django, and I want to secure it against multying. </p>
  
  <p>I have already set up a system for detecting multiple users on on IP, but I would also like to check whether two users have the same password (I don't want to know their plaintext passwords). </p>
  
  <p>Is this possible, seeing as Django uses salts randomised for each user?</p>