I'm not worried about it being a Ponzi or a Pyramid scheme but...

Everyone is pontificating on the economics of it, but what is the crypto doing? The client source code is there, nice... I guess... But that is just going to tell you or me that it's a client to solve a crypto puzzle block. What is it that it's doing? We're running a distributed computing app that works on blocks of a cryptographic puzzle and we don't know what the puzzle is. What are we actually doing with our computer cycles? What is it that we're actually decrypting or encrypting?