title: Generate a token for email verification in CodeIgniter 3
body: <p>I'm building a login/reg system in CI3 and I have a doubt.
  Instead of use:</p>
  
  <pre><code>$key=md5(uniqid());
  </code></pre>
  
  <p>for sending key for email activation...can I use another method? I don't know, using database (mysql)? hash with SHA1 maybe?
  I don't want the most secure way, just a solution that is not fake as uniqid() is. 'Cause I know that id generated by uniqid() is not really random, so there is no reason to hash to md5 is simply...stupid.</p>
  
  <p>Thank you in advance.</p>