Protecting Small Keys in Authentication Protocols for Wireless Sensor Networks

Abstract

Wireless sensor networks provide solutions to a range of monitoring problems. However, they also introduce a new set of problems mainly due to small memories, weak processors, limited energy and small packet size. Thus only a very few conventional protocols can readily be used in sensor networks. This paper introduces efficient protocols to distribute keys in wireless sensor networks. We also show how to harden the protocol against brute force attacks on small security keys. This is achieved without the necessity of using traditional encryption. The proposed protocols guarantee that the new key is fresh and that the communicating nodes use the same key. The protocols were implemented in TinyOS and simulated using TOSSIM. Energy consumption and memory requirements are analysed in detail.