  Setting up a large-scale wireless sensor network is challenging, as firmware
must be distributed and trust between sensor nodes and a backend needs to be
established. To perform this task efficiently, we propose an approach named
Box, which utilizes an intelligent Faraday cage (FC). The FC acquires firmware
images and secret keys from a backend, patches the firmware with the keys and
deploys those customized images over the air to sensor nodes placed in the FC.
Electromagnetic shielding protects this exchange against passive attackers. We
place few demands on the sensor node, not requiring additional hardware
components or firmware customized by the manufacturer. We describe this novel
workflow, implement the Box and a backend system and demonstrate the
feasibility of our approach by batch-deploying firmware to multiple commercial
off-the-shelf sensor nodes. We conduct a user-study with 31 participants with
diverse backgrounds and find, that our approach is both faster and more
user-friendly than firmware distribution over a wired connection.
