Wireless ad hoc network is formed by a group of mobile hosts that communicate through radio transmissions. In the hostile environment, this kind of network is vulnerable to traffic analysis which allows the adversary to trace the routing messages and the sensitive data packets. So, anonymous routing protocol for ad hoc networks is an important thing and has attracted more and more attention recently.

In this paper, we propose a novel, secure, and anonymous source routing, called SADSR (Secure and Anonymous Dynamic Source Routing) based on DSR. During the routing request of the SADSR, in order to hide the identity, the source node uses its current pseudonym to sponsor the routing request. And it uses the hash value of the changing share key between the source and destination as the tag of the destination. Meanwhile, it employs an initialized Bloom Filter as the routing record table to record the route. When the intermediate nodes receive the routing request, it randomly chooses a secret key and adds its identity into the Bloom Filter with seeding the secret key. So, when the destination node receives the routing request, the Bloom Filter has recorded the route information. Because the feature of the pseudonym employed in our scheme, the destination node can authenticate the source node and updates their share secret key when it replies to the routing request. During the routing reply phase, the intermediate node can determine whether it is the router by checking the Bloom Filter in the reply packet. The router applies the pseudonym based signature to protect the message during the routing reply phase, which makes sure that the neighborhood node en route can authenticate the upstream node and does not disclose its identity. SADSR also contains the routing maintenance and secure anonymous data transmission which are separately used by the end-to-end validate mechanism and HMAC strategy.

The performance of security and anonymity of SADSR is analyzed by both in theory and simulation. Compared to the other anonymous routing protocols, SADSR is not only an anonymous routing protocol, but also a secure one. It can provide authentication and integrity, anonymous neighborhood, identity anonymity, and route anonymity. The simulation results using NS-2 indicate that though SADSR is a secure and anonymous routing protocol, but the efficiency of SADSR is close to the secure routing protocol SDSR and anonymous routing protocol AnonDSR.