The encryption is all handled client side and explained in the papers and in the code (encrypt library). It is a form of convergent encryption and chunking. The network cannot decrypt the data, neither could any human without the keys (barring of course some massive code error etc. like any system). The code is all open source and audited by many devs universities and other parties. You can take a look and see how we have done some of these things, it is pretty good we think.

The point of the whole thing is you are in control, you and the machine, no humans and no intermediaries. That is a more natural way to work and very scalable.