A Trust Model Based on Cloud Theory in Underwater Acoustic Sensor Networks

Underwater acoustic sensor networks (UASNs) are susceptible to a large number of security threats, e.g., jamming attacks at the physical layer, collision attacks at the data link layer, and DoS attacks at the network layer. Because of the communication, computation, and storage constraints of underwater sensor nodes, traditional security mechanisms, e.g., encryption algorithms, are not suitable for UASNs. A trust model has been recently suggested as an effective security mechanism for open environments such as terrestrial wireless sensor networks (TWSNs), and considerable research has been done on modeling and managing trust relationships among sensor nodes. However, the trust models proposed for TWSNs cannot be directly used in a UASN due to its unique characteristics such as unreliable acoustic channel, dynamic network structure, and weak link connectivity. In this paper, we propose a novel trust model based on cloud theory (TMC) for UASNs. The objective of TMC is to solve uncertainty and fuzziness of trust based on cloud theory, which ultimately improves trust evaluation accuracy. Moreover, simulation results demonstrate that our algorithm outperforms other related works in terms of detection ratio of malicious nodes, successful packet delivery ratio, and network lifetime.