Physical Layer Key Sharing for an Off-The-Shelf UWB Module

Physical Layer Key sharing has become a popular topic in today's literature, as it could act as an alternative to computationally expensive RSA protocols. Its importance is emphasized by a number of resource-constrained, battery-powered autonomous robots and personal devices which need to communicate with a wider network. Physical layer key sharing often explores using temporally and spatially variant characteristics of a signal, such as a Wi-fi's channel state information, to produce the same secret keys at different devices. In recent years, Decawave has released an off-the-shelf plug-and-play ultrawideband (UWB) module, which has opened up new possibilities for key sharing. In this paper, we demonstrate how the channel impulse response (CIR) produced by the Decawave module is able to produce secret keys with a bit agreement rate(BAR) of over 89% at different devices in a network. In addition, we provide detailed information on the CIR and the BAR in different real-life environments as well as different scenarios in those environments. Finally, we examine the effect of different types of attackers and show that our system maintains a high level of security. Our paper aims to pioneer a new branch of UWB physical layer key-sharing, which utilizes off-the-shelf modules compared to complex and time-consuming setups.

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