• attack
• cc2420
• countermeasure
• denial of service
• gts
• ieee 802.15.4
• security
• wireless sensor network

Abstract

The IEEE 802.15.4 standard provides a framework for low data rate communications systems, typically sensor networks. It has the advantage to fit different applications requirements by adequately setting its parameters. When enabling its beacon mode, the protocol makes it possible to guarantee Quality of Service (QoS) by using its Guaranteed Time Slot (GTS) mechanism. In particular, a GTS slot can be granted to single network nodes, thus allowing them to access the medium without colliding each other. However, the GTS mechanism suffers from a security weakness. That is, it makes considerably easier for an adversary to perform a selective jamming attack to the network.
In this thesis work a countermeasure to selective GTS attack has been implemented. The countermeasure aims at significantly reducing the effectiveness of selective jamming in presence of GTS. First of all, the IEEE 802.15.4 security sublayer has been extended to enable MAC command and beacon frames encryption and authentication. Then, secured MAC command and beacon frames, in conjunction with a different GTS management, have been used to solve the security weakness. Secondly, the countermeasure has been tested by means of the implementation of a simple application and in a realistic attack scenario. Finally, we evaluate performance both in the presence and absence of the countermeasure and show the effectiveness of proposed solution.