12 digit unique pass code

[johnsmith153]

Hi,

 

I need to generate a unique 12 digit code.

 

ideally in the format: HBRQLPJKNMYT

 

It MUST be unique - so time() sounds possible.

 

However, time() wouldn't be good as obviously someone could guess this easily.

 

Any ideas?

[gevans]

<?php
function uuid(){
        $uid = strtoupper(md5(uniqid(rand(), true)));
        $uuid = substr($uid, 0, 12);
        return $uuid;
}
?>

[johnsmith153]

Perfect.