Capture detection

Abstract

The previous chapter looked at the security of WSNs from the single node perspective. We proposed a new probabilistic protocol for the node authentication and the communication confidentiality. Given that in our solution a secret key can be shared between more than two nodes, the attacker that physically captures a node is potentially able to compromise the confidentiality of a fraction of network communications. Actually, one of the most vexing problems for WSNs security is the node capture attack: An adversary can capture a node from the network eventually acquiring all the cryptographic material stored in it. Further, the captured node can also be reprogrammed by the adversary and re-deployed in the network in order to perform malicious activities. This chapter addresses the node capture attack in mobile WSNs. In particular, we start from the intuition that mobility, in conjunction with a reduced amount of local cooperation, helps to compute, effectively and with a limited resource usage, the global security properties of the network. Then, we develop this intuition and use it to design a protocol that the network nodes can use to detect the node capture attack.We support our proposal with a wide set of experiments, showing that mobile networks can leverage mobility to compute global security properties, like node capture detection, with a small overhead.