Establishing Trust between Nodes in Mobile Ad-Hoc Networks

Civil protection organizations like firefighters or police rely on mobile personnel capable of solving tasks in exceptional scenarios. Wireless mobile and ad-hoc communication equipment can be used to support operations in areas of collapsed or unavailable communication infrastructures. Mobile ad-hoc networks rely on routing protocols where each individual device becomes a node of the network. Existing routing protocols concentrate on establishing an efficient distribution of routing information and on routing of messages. However, the particular properties of mobile ad-hoc networks enable various new attacks, in particular targeting routing. Conventional security mechanisms fail to cope with the arising security challenges. Identification of each device and trust relationships between devices become an important function of the complete network. This paper proposes to apply well-known security mechanisms and concepts from the domain of trusted computing in order to establish trust between devices. Attestation of devices is integrated into the mobile ad-hoc network routing protocol and building on this, transmission of routing- and payload data can be restricted to identified devices in trustworthy states. Thus, malicious devices can be automatically recognized by all devices and excluded from participation in the network. Especially the dissemination of misleading routing information, which affects the availability of the whole network, is effectively prevented. A prototypical implementation and first tests in a mobile ad-hoc network test-bed, consisting of nodes equipped with a Trusted Platform Module, demonstrate the feasibility of the approach. The challenges and room for improvement in terms of timing and efficiency are also discussed.