title: Hashing or encrypting variables to be sent in a url
body: <p>I have a link which needs to be generated so that it can be placed in an email. When the user clicks on this link, the system is meant to match the code sent in the email to a user, so it can pull up the records for that user.</p>
  
  <p>However, I am not quite sure which encryption/hashing method to use. For the login for the admin system on this site, I use PBKDF2 in the database for the password (with salting) and AES encryption when it is sent to the session variables, but I don't know if the characters used by PBKDF2 &amp; AES are url compatible.</p>
  
  <p>Basically, I need the best method of hashing/generating a random code for storage in the database and  an encryption method so that I can place a year and the code (which I previously mentioned) in a url. I am using PHP and MySQL if that helps.</p>
  
  <p>What do you guys think?</p>