Formal specifications of Denial of Service attacks in Wireless Sensor Networks

Wireless Sensor Networks (WSN) are composed of small, low cost, resource-constrained computing nodes equipped with low power wireless transceivers. Their unattended nature and possible deployment in hostile environmental conditions poses several challenges in ensuring that a WSN is formed effectively and survives long enough to fulfill its function. WSN nodes are vulnerable to many Denial of Services(DoS) attacks. To secure WSN still against attacks many innovative solutions/protocols have been proposed. However, a number of ambiguities exist in the definition of these DoS attacks. To remove these ambiguities and to clarify our specifications we represented the DoS attacks in a formal modeling notation Z. The specifications are written in a bottom-up approach starting from the basic definitions (like node, message etc), specifying simple operations of WSN (like receive, transmit etc), complex operations (like eavesdrop key, node capture etc) and going all the way up to formally define the DoS attacks. Different WSN routing protocols are then specified to confirm their vulnerability against DoS attacks. Use of Formal methods, thus, confirms how vulnerable a particular routing protocol is against a particular attack. This is a novel work and to the best of our knowledge DoS attacks have not yet been formally defined.