STUN: Secret-Free Trust-Establishment For Underground Wireless Networks

Emerging agricultural internet-of-things (Ag-IoT) is increasing the efficiency of farming. The data collected by the wireless-enabled Ag-IoT infrastructure is highly sensitive as corrupting the data can cause significant damages to farm production and the livelihood of growers. The trust of the data can be established by initial secure bootstrapping of the wireless underground end nodes. This paper tackles the problem of scalable and secret-free trust-establishment for commercial off-the-shelf (COTS) underground nodes with an aboveground gateway applicable to heterogeneous end nodes. Secure boot-strapping requires authentication and secret establishment, which are achieved in-band, aided by a trusted underground node by exploiting the unique and hard-to-forge underground wireless signal propagation laws. The secret-free trust-establishment for underground wireless networks (STUN) protocol is resistant to active signal injection attacks and is scalable with an increasing number of underground nodes. Further, it is theoretically proven that STUN has security equivalent to the unbalanced oil and vinegar scheme in public cryptography. STUN is validated based on experimental data from an underground wireless testbed.