What mechanisms exist already for designing a P2P architecture, in which the different nodes do work separately, in order to split a task (say distributed rendering of a 3D image), but unlike torrents, they don’t get to see, or hijack the contents of the packets being transmitted? Only the original task requester is entitled to view the? results of the complete task.
Any working implementations on that principle already?
EDIT: Maybe I formulated the question wrongly. The idea is that even when they are able to work on the contents of the separate packets being sent, the separate nodes never get the chance to assemble the whole picture. Only the one requesting the task is supposed to do this.
If you have direct P2P connections (no “promiscuous” or “multicasting” sort of mode), the receiving peers should only “see” the data sent to them, nothing else.
If you have relay servers on the way and you are worried that they can sniff the data, I believe encryption is the way to go.
What we do is that peer A transmits data to peer B in an S/MIME envelope: the content is signed with the Private Key of Peer A and encrypted with the public Key of Peer B.
Only peer B can decrypt the data and is guaranteed that peer A actually sent the data.
This whole process is costly CPU and byte wise and may not be appropriate for your application. It also requires some form of key management infrastructure: peers need to subscribe to a community which issues certificates for instance.
But the basic idea is there: asymetric encryption with a key or shared secret encryption.