protected function _getHmacKey(Mage_Core_Model_Store $store)
    {
        $adyenHelper = Mage::helper('adyen');
        switch ($adyenHelper->getConfigDataDemoMode()) {
            case true:
                $secretWord = trim($adyenHelper->getConfigData('secret_wordt', 'adyen_hpp'));
                break;
            default:
                $secretWord = trim($adyenHelper->getConfigData('secret_wordp', 'adyen_hpp'));
                break;
        }

        return $secretWord;
    }