/**
  * @see AbstractKeyInstance::serializeToObject($obj)
  */
 protected function serializeToObject(&$obj)
 {
     $key = $this->rsa->getPublicKey(CRYPT_RSA_PUBLIC_FORMAT_RAW);
     $obj["n"] = $key["n"]->toString();
     $obj["e"] = $key["e"]->toString();
 }