Automatic analysis of distance bounding protocols

Distance bounding protocols are used by nodes in wireless networks for the crucial purpose of estimating their distances to other nodes. This typically involves sending a request by one node to another node, receiving a response, and then calculating an upper bound on the distance by multiplying the round-trip time with the velocity of the signal. However, dishonest nodes in the network can turn the calculations both illegitimate and inaccurate when they participate in protocol executions. Therefore, it is important to analyze protocols for the possibility of such violations. Past efforts to analyze distance bounding protocols have only been manual. However, automated approaches are important since they are quite likely to find flaws that manual approaches cannot, as witnessed many times in the literature of key establishment protocols. In this paper, we use the constraint solver tool to automatically analyze distance bounding protocols: We first formulate a new trace property called Secure Distance Bounding (SDB) that protocol executions must satisfy. We then classify the scenarios in which these protocols can operate considering the (dis)honesty of nodes and location of the attacker in the network. Finally, we extend the constraint solver tool so that it can be used to test protocols for violations of SDB in those scenarios and illustrate our technique on several examples that include new attacks on published protocols. We also hosted an on-line demo for the reader to check out our implementation.