R-CARP: A Reputation Based Channel Aware Routing Protocol for Underwater Acoustic Sensor Networks.

In this paper we introduce R-CARP, a reputation based channel aware routing protocol for underwater acoustic sensor networks (UASNs). While many routing protocols have been proposed for UASNs, solutions to secure routing protocols from attacks such as sinkhole attack and selective forwarding are still overlooked. These routing attacks can dramatically disrupt network performance, especially in some application scenarios such as homeland security and critical infrastructure monitoring, where a high reliability on message delivery is required. Designing secure and reliable protocols for UASNs is particularly challenging due to acoustic modems unique characteristics such as low bandwidth and bit rate, high propagation delays and high energy consumption when in transmit mode. The aim of this work is therefore to propose R-CARP, a secure and reliable routing protocol tailored to such communication constrained environment. R-CARP is an improved version of CARP, the channel aware routing protocol presented in [5], enriched with a reputation based mechanism to contrast malicious node behavior. To secure R-CARP we employ BLS, a short digital signature algorithm, exploiting its aggregation property to reduce the additional communication overhead. By means of simulation based performance evaluation, we show that, under attack, R-CARP is effective at bypassing malicious nodes and outperforms CARP in terms of packet delivery ratio (PDR) and energy per bit (EPB) by a factor of up to 2, at the cost of a slight increment in terms of latency.