title: PHP: Mcrypt - which mode?
body: <p>I've been testing out the various <a href="http://www.php.net/manual/en/mcrypt.constants.php" rel="nofollow noreferrer">modes</a> available in PHP's <code>mcrypt</code> function. <em>ECB</em>  is the mode used in most tutorials, but isn't recommended by both the just linked page and <a href="https://stackoverflow.com/questions/2809855/which-php-mcrypt-cipher-is-safest">some users</a>, so I reckon that either <em>CBC</em> or <em>CFB</em> should do the trick.</p>
  
  <p>The PHP documentation isn't too fat in it's comparision of the different modes available to <code>mcrypt</code> and instead refers to the book of <em>'Applied Cryptography by Schneier'</em>, which I am not too keen to buy for the moment.</p>
  
  <p>So which of the <code>mcrypt</code>-modes do I want to use and why?</p>