protected function _decryptAndVerify($data, $isFile, $outputFile, $ignoreVerifyErrors = false)
    {
        $input  = $this->_prepareInput($data, $isFile, false);
        $output = $this->_prepareOutput($outputFile, $input);

        $this->engine->reset();
        $this->engine->setPins($this->decryptKeys);
        $this->engine->setInput($input);
        $this->engine->setOutput($output);
        $this->engine->setOperation('--decrypt');
        $this->engine->setProcessData('IgnoreVerifyErrors', $ignoreVerifyErrors);
        $this->engine->run();

        $return = array(
            'data'       => null,
            'signatures' => $this->engine->getProcessData('Signatures')
        );

        if ($outputFile === null) {
            $return['data'] = $output;
        }

        return $return;
    }