code: private static String wrapSymmetricKey(KeyPair wrapperKey, SecretKey symmetricKey) throws NoSuchPaddingException,
  	                                                                                          NoSuchAlgorithmException,
  	                                                                                          InvalidKeyException,
  	                                                                                          IllegalBlockSizeException {
  		Cipher cipher = Cipher.getInstance(WRAPPER_TRANSFORMATION);
  		cipher.init(Cipher.WRAP_MODE, wrapperKey.getPublic());
  		byte[] decodedData = cipher.wrap(symmetricKey);
  		return Base64.encodeToString(decodedData, Base64.DEFAULT);
  	}
docs: region Key Wrapping