title: PHP: generating unique string
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/1846202/php-how-to-generate-a-random-unique-alphanumeric-string">PHP: How to generate a random, unique, alphanumeric string?</a>  </p>
  </blockquote>
  
  
  
  <p>I'm trying to generate unique id (alpha-numeric string). I'm using curent timestamp for that. I have two questions:</p>
  
  <ol>
  <li>Will <code>md5(stamp1)</code> be different from <code>md5(stamp2)</code> if <code>stamp1 != stamp2</code>.</li>
  <li>Is there a common way to generate unique string?</li>
  </ol>
  
  <p><strong>PS:</strong> the easiest way of cause is to take stamp as id. Still I dont want that it was easy to find out how id is generated </p>