A Low-Cost Secure Neighbor Verification Protocol for Wireless Sensor Networks

Wireless networking relies on a fundamental building block, neighbor discovery (ND). However, the nature of wireless communications makes attacks against ND easy: an adversary can simply replay or relay (wormhole) packets across the network and mislead disconnected nodes they communicate directly. Such attacks can compromise the overlying protocols and applications. Proposals in the literature seek to secure ND, allowing nodes to verify they are neighbors. However, they either rely on specialized hardware or infrastructure, or offer limited security, often only against an attack mounted by at most two adversarial nodes (a 2-end wormhole). In this paper, we address these problems, designing a secure neighbor verification protocol for low-cost and constrained Wireless Sensor networks (WSN). Our scheme relies on nodes’ distance estimation and simple geometric tests, and it is fully distributed. We prove our protocol secure against the classical 2-end wormhole attack, and we show it makes it hard to mount a k-end wormhole attack (k > 2): For non-negligible yet limited chance of success, the adversary must know the locations of all victim nodes and deploy a relay (wormhole) node close to each victim. We provided a proof-of-concept implementation with off-the-shelf WSN equipment, Cricket Motes. The protocol is the first applicable method that achieves a high level of security for WSN against sophisticated wormhole attacks.