code: public static String unprotect(String data) {
          if(data==null)      return null;
          try {
              Cipher cipher = Secret.getCipher(ALGORITHM);
              cipher.init(Cipher.DECRYPT_MODE, DES_KEY);
              String plainText = new String(cipher.doFinal(Base64.getDecoder().decode(data.getBytes(StandardCharsets.UTF_8))), StandardCharsets.UTF_8);
              if(plainText.endsWith(MAGIC))
                  return plainText.substring(0,plainText.length()-3);
              return null;
          } catch (GeneralSecurityException | IllegalArgumentException e) {
              return null;
          }
      }
docs: Returns null if fails to decrypt properly.