protected function generateCheckSumDynamic() {
        return sha1(
                        sprintf("%s|%s|%s|%s|%s|%s|%s|%s|%s", $this->_merchantID, $this->_secretCode, $this->data->ic_amount, $this->data->ic_orderid, $this->data->ic_reference, $this->data->ic_currency, $this->data->ic_country, $this->data->ic_urlcompleted, $this->data->ic_urlerror
                        )
        );
    }