mbam

<?php
// EXAMPLE USAGE
$array = generate();
echo $array[0];
echo "<br />";
echo $array[1];


// FUNCTION
function generate()
{
   $digilist = "0123456789ABCDEFGHJKLMNPQRTUVWXY";

   //now we generate a new random ID number using the substrings of the digitList string above
   $id = NULL;
   $id .= substr($digilist, rand(1, 9), 1); //random number
   $id .= substr($digilist, rand(10, 31), 1); //then a letter
   $id .= substr($digilist, rand(10, 31), 1); //another letter
   $id .= substr($digilist, rand(1, 9), 1); //a number
   $id .= substr($digilist, rand(1, 9), 1); //and finally another number - simple :D

    //ok so now we need to generate an MD5 hash of our ID
   $hash = md5($id);

   //cycle through the hash 16 (length of key) times (in steps of 2 because each hex bytes is 2 digits long)
   $i = 0;
   $key = NULL;
   for ($i; $i < 32; $i+=2)
   {
      //here we convert the next hex value to an integer and perform a bitwise AND operation against '31'
      //31 is the highest substring value in our digit list.
      //more info on bitwise ops here: Bitwise operation - Wikipedia, the free encyclopedia
      $nextdigit = hexdec(substr($hash, $i, 2)) & 31;

      //if 'i' is divisable by 8 (every 4 cycles) then we want to add "-"
      if ((($i % 8) == 0) && ($i > 0))
      {
         $key .= "-".substr($digilist, $nextdigit, 1);
      }
      else
      {
         $key .= substr($digilist, $nextdigit, 1);
      }
   }

   $array = array($id, $key);
   //return
   return $array;
}
?>