Rebound: Decoy routing on asymmetric routes via error messages

Decoy routing is a powerful circumvention mechanism intended to provide secure communications that cannot be monitored, detected, or disrupted by a third party who controls the user´s network infrastructure. Current decoy routing protocols have weaknesses, however: they either make the unrealistic assumption that routes through the network are symmetric (i.e., the router implementing the decoy routing protocol must see all of the traffic, in both directions, from each connection it modifies), or their protocol requires modifying the route taken by packets in connections that use the protocol, and these route changes are detectable by a third party. We present Rebound, a decoy routing protocol that tolerates asymmetric routes without modifying the route taken by any packet that passes through the decoy router, making it more difficult to detect or disrupt than previous decoy routing protocols.