ARDEN: Anonymous networking in delay tolerant networks

Delay Tolerant Networks (DTNs) provide a communications infrastructure for environments lacking continuous connectivity. Such networks rely on the mobility of nodes and the resulting opportunistic connections to carry messages from source to destination. Unfortunately, exchanging packets with an arbitrary intermediary node makes privacy difficult to achieve in these systems as any adversary can easily act as an intermediary and determine the sender and receiver of a message. In this paper, we present ARDEN, an anonymous communication mechanism for DTNs based on a modified onion routing architecture. Instead of selecting specific nodes through which messages must pass as is traditionally done in onion routing, ARDEN uses Attribute-Based Encryption (ABE) to specify and manage groups that may decrypt and forward messages. Through simulation, we show that this approach not only increases throughput and reduces end-to-end latency over traditional onion routing techniques, but also adds minimal overhead when compared to DTN routing protocols that do not provide anonymity guarantees. Through this, we show that ARDEN is an effective solution for anonymous communication in intermittently connected networks such as DTNs.