private function encode($data)
    {
        $rdm = $this->random();
        $data = base64_encode($data);
        $startIndex = rand(1, strlen($rdm));
        $params = base64_encode($startIndex).self::ENC_SEPARATOR;
        $params .= base64_encode(strlen($data)).self::ENC_SEPARATOR;

        return $params.substr_replace($rdm, $data, $startIndex, 0);
    }