public function isAuthenticated()
    {
        $authenticated = false;

        if (is_null($this->parameters)) {
            return $authenticated;
        }

        $calculatedHash = md5(
            $this->parameters['item'] . '|' .
            $this->parameters['page'] . '|' .
            $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey']
        );

        if ($this->parameters['hash'] === $calculatedHash) {
            $authenticated = true;
        }

        return $authenticated;
    }