More and more games are going the data driven route which means that there needs to be a layer of security around easy manipulation. I've seen it where games completely bundle up their assets (audio, art, data) and I'm wondering how they are managing that? Are there applications / libraries that will bundle and assist you with managing the assets within? If not is there any good resources that you would point to for packing / unpacking / encryption?

This specific question revolves around C++, but I would be open to hear how this is managed in C#/XNA as well.

Just to be clear -- I'm not out to engineer a solution to prevent hacking. At the fundamental level we're all manipulating 0's and 1's. But, we do want to keep the 99% of people that play the game from simply modifying XML files that are used to build the game world. I've seen plenty of games bundle all of their resources together. I'm simply curious about the methods they're using.