NEKAP: Intruder Resilient and Energy Efficient Key Establishment in Sensor Networks

Hop-by-hop authentication in wireless sensor networks (WSNs) prevents outside intruders from taking part in the network and launching attacks. Due to resource constraints of WSNs, standard key distribution schemes are not applicable. Such networks require resilience when intruders compromise a key. This paper presents NEKAP - neighborhood-based key agreement protocol, a key distribution protocol for WSNs. NEKAP is intruder resilient: an intruder that compromises a key has access to the links of a limited neighborhood, and not to those in other regions of the network. NEKAP is energy-efficient in that only a few messages are exchanged in small neighborhoods to establish the keys. The paper presents the protocol and algorithms, make a security analysis, compare it with other protocols in the literature and shows one implementation for the TinySec platform.