A Reputation-Based AODV Protocol for Blackhole and Malfunction Nodes Detection and Avoidance

Enhancing the security of Wireless Sensor Networks (WSNs) improves the usability of their applications. Therefore, finding solutions to various attacks, such as the blackhole attack, is crucial for the success of WSN applications. This paper proposes an enhanced version of the AODV (Ad Hoc On-Demand Distance Vector) protocol capable of detecting blackholes and malfunctioning benign nodes in WSNs, thereby avoiding them when delivering packets. The proposed version employs a network-based reputation system to select the best and most secure path to a destination. To achieve this goal, the proposed version utilizes the Watchdogs/Pathrater mechanisms in AODV to gather and broadcast reputations to all network nodes to build the network-based reputation system. To minimize the network overhead of the proposed approach, the paper uses reputation aggregator nodes only for forwarding reputation tables. Moreover, to reduce the overhead of updating reputation tables, the paper proposes three mechanisms, which are the prompt broadcast, the regular broadcast, and the light broadcast approaches. The proposed enhanced version has been designed to perform effectively in dynamic environments such as mobile WSNs where nodes, including blackholes, move continuously, which is considered a challenge for other protocols. Using the proposed enhanced protocol, a node evaluates the security of different routes to a destination and can select the most secure routing path. The paper provides an algorithm that explains the proposed protocol in detail and demonstrates a case study that shows the operations of calculating and updating reputation values when nodes move across different zones. Furthermore, the paper discusses the proposed approach’s overhead analysis to prove the proposed enhancement’s correctness and applicability.