title: Function to generate access token to be used in web service authentication
body: <p>I need a php function that generates access token to uniquely identify users. I will store this token in an extra column named "token" and I will use it for authentication with mobile app. I searched for it online and all results refer to either twitter or facebook. I need it in my app.</p>
  
  <p>I use cakePHP backend and Android platform.</p>
  
  <p>Thanks a lot.</p>