ABSTRACT
In this chapter, we will consider key establishment protocols for wireless sensor networks. Several protocols have been proposed in the literature for the establishment of a shared group key for wired networks. The choice of a protocol depends whether the key is established by one of the participants (and then transported to the other[s]) or agreed among the participants, and on the underlying cryptographic mechanisms (symmetric or asymmetric). Clearly, the design of key establishment protocols for sensor networks must deal with different problems and challenges that do not exist in wired networks. To name a few, wireless links are particularly vulnerable to eavesdropping, and that sensor devices can be captured (and the secrets they contain can be compromised); in many upcoming wireless sensor networks, nodes cannot rely on the presence of an online trusted server (whereas most standardized authentication and key establishment protocols do rely on such a server).
