A Security System for Spreading Information About Malicious Behaviors in Underwater Wireless Sensor Networks

Despite being often used in mission critical scenarios, such as surveillance and coastal monitoring, Underwater Acoustic Networks (UANs) are inherently vulnerable to Denial of Service (DoS) attacks performed by malicious nodes. With enough knowledge about the communication protocol, reputation systems are proven to be effective on identifying misbehaviors in the network [1], [2]. However, while a node can assess the behavior of a neighbor node with high accuracy, it might have poor or no information about nodes deployed a few hops away. Moreover, given the disastrous consequences that DoS attacks may have on UANs, information about the presence of an intruder must be notified and spread across the network as quickly as possible, in order to permit countermeasures to be put in place and without impacting the performance of the UAN. In this paper we present UWSentinel, a transparent layer, i.e., independent of the reputation mechanism, added to the DESERT Underwater protocol stack to alert all nodes in the network of a possible threat, such as a malicious node performing a DoS attack. Results from simulations show that our protocol is lightweight and has little impact on the network throughput, while being comparatively fast in alerting all the nodes in the network, providing them with information about the possible misbehaving node.