title: Ruby on Rails gem to make passwords more secure?
body: <p>I built a Ruby on Rails authentication system from scratch and it works great.</p>
  
  <p>(I am aware of the existence of <code>Devise</code>, yet I wanted to write my own system to get a better grasp of Ruby on Rails in general.)</p>
  
  <p>The only thing that worries me is users who pick words from dictionaries, sequential numbers (e.g. "12345679"), their own user names, or the all-time classic "password" as their own <code>password</code>.</p>
  
  <p>Is there a gem that validates against any of those? Or will I have to work with regular expressions here?</p>
  
  <p>Thanks for any help.</p>