Php encryption

<?php
        $un = 'wilbert';
        $pw = 'P@ssw0rd';
        $pk1 = '1961b7e6fc325ca0fb36b94ff57e1e97';
        $pk2 = '162d6efd96fd97c7569c2a27b8bf82e6';
        $pk3 = '0a1a46a08e1e30bf90b93530ffee8a03';
        $ul = strlen($un);
        $pl = strlen($pw);
        $sl = $ul^$pl<10;
        $i = 0;
        $pc = 1;
        while(isset($pw{$i}))
        {
                $pc += ord($pw{$i});
                $i++;
        }
        $pn = round(sqrt($pc*$sl*$pl)*99999);
        $md5 = '';
        if($pl == 5) $md5 = md5($pn . $pk3 . $un . $pw . $pc . $pk2);
        if($pl == 6) $md5 = md5($ul . $pk1 . $pc . $pw . $pk3);
        if($pl == 7) $md5 = md5($pn . $pk3 . $un . $pc . $pk2);
        if($pl == 8) $md5 = md5($un . $pw . $pk3 . $un . $pc . $pk1 . $pk3);
        if($pl >= 9) $md5 = md5($pn . $pk2 . $un . $pc . $pk2 . $pn);
        echo $md5;
?>