Serializer serializer = new Persister(); SerializerBuilder builder = serializer.getBuilder(); builder.setFeature("http://xml.org/sax/features/external-general-entities", false); builder.setFeature("http://xml.org/sax/features/external-parameter-entities", false); String plaintext = "<root>Hello, World!</root>"; Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, secretKey); byte[] encryptedData = cipher.doFinal(plaintext.getBytes()); Signature signature = Signature.getInstance("SHA256withRSA"); signature.initSign(privateKey); signature.update(plaintext.getBytes()); byte[] signatureBytes = signature.sign();