bueno aqui te dejo otro
Código PHP:
$con = "BCDFGHJKLMNÑPQRSTVWXYZ";
$voc = "AEIOU";
$num ="1234567890";
for ($x=0; $x < 6; $x++) {
$con[$x] = substr($con, mt_rand(0, strlen($con)-1), 1);
$voc[$x] = substr($voc, mt_rand(0, strlen($voc)-1), 1);
$num[$x] = substr($num, mt_rand(0, strlen($num)-1), 1);
}
$pass = $con[0] . $num[0] .$voc[0] . $num[0] . $num[0] . $voc[0] ;
echo $pass;
Un Saludo