protected function _generate_short_code($id, $length = 6, $randomizer = '171823')
    {
        // Get the randomized number based on $id
        $number = bcmod(bcmul($id, $randomizer), bcpow(10, $length));

        // Make sure number id is long enough and it's length is even
        $length = max(strlen($number), $length) + (max(strlen($number), $length) % 2);
        $number = str_pad($number, $length, '0', STR_PAD_LEFT);

        $vowels = 'aeiou';
        $consonants = 'bcdfghjklmnpqrstvwxyz';
        $short_code = '';

        // Parse the id
        for ($i = 0; $i < $length; $i = $i + 2)
        {
            $slice = substr($number, $i, 2);
            $num = intval($slice);

            $vowel_index = intval(floor($num / strlen($consonants)));
            $consonant_index = $num % strlen($consonants);

            $short_code .= $vowels[$vowel_index].$consonants[$consonant_index];
        }

        return $short_code;
    }