How to make game save that will can be port to other platforms

Windows
1

Hi!

I want to add possibilty to save progress in my game. I just need save some information about unlocked levels. I try use code from https://github.com/CartBlanche/MonoGame-Samples/blob/master/Storage/SaveGame.cs but didnt work anymore.

I have three assumptions about game save:
*Not readable for players (XMLSerialization isn’t good idea)
*Hard to be edited
*Working on most platform (if its possible)

2

Maybe binary serialiser? http://msdn.microsoft.com/en-us/library/c5sbs8z9(v=vs.110).aspx
or protobuf https://code.google.com/p/protobuf-net/

Or just use whatever is easiest and use an encrypted stream?

3

It will work on most platform? Where i should serialize something eg on Windows Phone 8 device?