Formal Verification of a Key Agreement Protocol for Wireless Sensor Networks

Wireless sensor networks (WSNs) have gained much attention in both industry and research communities where they are expected to bring the interaction between humans, environment, and machines to a new level. Due to the resource constraints of sensors nodes, it is infeasible to use traditional key establishment techniques that find use in fixed communication systems. In recent years a number of group key agreement protocols have been proposed for resourcelimited wireless sensor devices. However, these protocols do not satisfy some important security properties such as mutual authentication and forward secrecy. In this paper, we propose a hybrid authenticated group key agreement protocol for WSNs. This hybrid protocol reduces the high cost public-key operations at the sensor side and replaces them with efficient symmetric-key based operations. In order to provide assurance that the proposed protocol is verifiably secure and trustworthy, a formal verification is performed on the protocol´s design specification.