TinySARP: A secure routing protocol for wireless sensor networks based on trust metrics

Wireless sensor networks (WSNs) are quite different from traditional wireless networks. While traditional wireless networks have been designed to support longer ranges and higher throughput, wireless sensor networks are being designed to achieve longer node lifetimes and minimized resource usage. Wireless sensor network nodes are typically physically small, have a limited energy supply (usually in the form of a battery), and the network themselves do not accommodate high throughput applications. Due to the strict limitations of WSN nodes, it is a greater challenge to ensure security on the network relative to traditional wireless networks. Traditional wireless network nodes are capable of performing complex cryptographic operations and employing sophisticated security mechanisms. Such tasks are not possible on WSN nodes due to their inherent limitations. Additionally, the physical compromise of nodes is a greater threat in a WSN due to the limited protection that is provided.;While much research has been conducted to investigate and develop secure routing protocols specifically for wireless sensor networks, all of these efforts assume that the routing protocol already has knowledge of a physically compromised node; no known protocol can detect a physically compromised node in the network. In this regard. TinySARP, short for Tiny Secure Acknowledgment Routing Protocol, has been developed. The protocol uses a combination of a unique set of packets, called secure acknowledgment requests and secure acknowledgments, and trust metrics to determine whether a node in the neighborhood has been physically compromised. Results show that TinySARP is capable of thwarting many of the major attacks that can be employed by an adversary that has physically compromised a node. Additionally, experiments show that the average power consumption of TinySARP is only 9% more than that of a standard protocol provided in the TinyOS-2.x tree.