Energy cost of cryptographic session key establishment in a wireless sensor network

This paper presents an energy cost analysis for session key establishment in a wireless sensor network (WSN). A session key is used to encrypt the data between two nodes and it should be established before the start of their secure data communication. In a WSN, the session key establishment is an important process in constructing a secure data communication and is preferably undertaken to minimize the energy drain on the energy-constrained sensor node. In our study, we examine the energy cost of session key establishment using a symmetric-key based protocol in a WSN. We make use of an energy consumption model for the sensor node that considers the communication cost and computational cost for implementing the protocol on a microcontroller-based sensor node. In particular, we explore the effects of session key establishment to the overall energy cost in a sensor node, especially considering the frequency of key establishment and the quality of communication channel.