One node knows the source of coins, one knows the destination, but neither knows both.
Hope I unnested this correctly...
TOR uses 3 hops. That way the nodes don't even know which part of the line they are... Each bundle of sticks comes from unknown source, to unknown destination, if any. Only the exit nodes have kind of a clue, and they're 2 hops away with no hope... Since we're dealing with a 2.5min mem pool, timing analysis becomes utterly hopeless. DRK is fuckin' beautiful.