about Encryption Library

OK now I solution this way if you better way pls tel me thank you

PHP Code:

public function encode_me($string, $key = '') {
        $this->load->library('encryption');
        return rtrim(strtr(base64_encode( $this->encryption->encrypt($string) ), '+/', '-_'), '=');
    }

    public function decode_me($string, $key = '') {
        $this->load->library('encryption');
        return $this->encryption->decrypt( base64_decode(str_pad(strtr($string, '-_', '+/'), strlen($string) % 4, '=', STR_PAD_RIGHT)) );
    }