NB-IoT Battery Depletion via Malicious Interference

Narrowband Internet of Things (NB-IoT) is a popular Low Power Wide Area Network (LPWAN) technology for large-scale Internet of Things (IoT) applications. The NB-IoT protocol is designed to conserve energy, so battery powered devices can have a lifetime of several years. However, the protocol design does not assume malicious interference. As we show in this paper jamming can be used to deplete the battery of NB-IoT devices reducing the lifetime from many years to several month. These attacks can be carried out without preventing data delivery entirely and are therefore hard to detect. We consider jamming focused on the initial unprotected downstream communication after a node wakes from sleep. We show that the most efficient interference can be constructed by exploiting the capture effect; the attacker can replace a subframe within the transmission from the base station to the device.