Protecting Wireless Sensor Networks Against Sybil Attacks

Wireless sensor networks (WSNs) are a central component of the Internet of Things (IoT), offering various applications including environmental monitoring, military surveillance, and smart cities. However, WSNs suffer from limited energy and computing resources, making them vulnerable to threats such as Sybil attacks, in which a malicious node generates multiple fictitious identities to exploit legitimate nodes, disrupt routing and degrade performance. In this paper, we address this vulnerability in the context of the Equitable Distribution Energy (EDE) protocol, a modified version of LEACH that introduces a transfer node (TN) responsible for transferring data between the cluster head (CH) and the base station (BS) in order to reduce the charge on CH and balance energy consumption. We propose a defense approach that combines lightweight authentication, RSSI-based detection, and trust management to detect and mitigate Sybil nodes. Simulation results demonstrate that the proposed approach increases the packet delivery ratio (PDR), significantly reduces energy waste and improves network reliability.