I gave you a link to freehaven.net bibliography and you said it was too academic for you . I will let you know when the Tor pop up book comes out . (JK you are cool, just joking with you ) BTW it is Tor not TOR. It is no longer considered to be an acronym for The Onion Router, and actually many experts would argue that it isn't even an onion router (although pretty much everyone still calls it one). Onion Routing involves layer encrypting data using the public keys of many nodes, the final ciphertext block is called an onion. Then the block is routed around by nodes, which are onion routers, each removing a layer. Tor builds telescoping encrypted tunnels through a series of nodes and then routes the data through this multi-layered tunnel. You could argue that this is largely a different way to describe pretty much the same thing, but there are fundamental differences. Also you could argue that any layer encryption based routing system is onion routing, but I2P calls their system garlic routing ;P. Freenet takes single layer encrypted ciphertext blocks and routes them through series of single layer encrypted tunnels. I dunno what they call their technique.