Smart dust, friend or foe?--Replacing identity with configuration trust

Smart dust motes are miniature self-contained systems that may be deployed in very large numbers. In military applications these devices are subject to different threats than conventionally deployed systems, for example, attackers may deploy counterfeit devices to subvert the integrity of a system, and this may be a greater concern that confidentiality. The possibility of identity theft reduces the value of conventional authentication methods, prompting a reevaluation of how to achieve integrity in such systems. This paper reviews the authentication problem from first principles, but instead of regarding each pairwise network interaction separately, it shows how to build Configuration Trust in a system as a whole. The new trust process focuses on establishing the type or function of a device, rather than individual identity, supported by key distribution that introduces just sufficient diversity to detect subverted motes. This is embodied in protocols that establish communication with a mote and manage the system configuration. These protocols are shown to be effective in defeating standard communication attacks, and a detailed analysis demonstrates their strength in the face of an attack by overwhelming numbers of counterfeit motes. The paper concludes by illustrating the use of this trust mechanism in a simulated dust war. The simulation results confirm that this Configuration Trust system is robust, even under aggressive attack. 2004 Elsevier B.V. All rights reserved.