SNAP: Proximity Detection with Single-Antenna IoT Devices

THaW graduate Tim Pierson will present SNAP, a method for proximity detection with single-antenna IoT devices at MobiCom in October.

SNAP - Likelihood of declaring proximityAbstract: Providing secure communications between wireless devices that encounter each other on an ad-hoc basis is a challenge that has not yet been fully addressed. In these cases, close physical proximity among devices that have never shared a secret key is sometimes used as a basis of trust; devices in close proximity are deemed trustworthy while more distant devices are viewed as potential adversaries. Because radio waves are invisible, however, a user may believe a wireless device is communicating with a nearby device when in fact the user’s device is communicating with a distant adversary. Researchers have previously proposed methods for multi-antenna devices to ascertain physical proximity with other devices, but devices with a single antenna, such as those commonly used in the Internet of Things, cannot take advantage of these techniques.

We present theoretical and practical evaluation of a method called SNAP — SiNgle Antenna Proximity — that allows a single-antenna Wi-Fi device to quickly determine proximity with another Wi-Fi device. Our proximity detection technique leverages the repeating nature Wi-Fi’s preamble and the behavior of a signal in a transmitting antenna’s near-field region to detect proximity with high probability; SNAP never falsely declares proximity at ranges longer than 14 cm.

In Proceedings of the ACM International Conference on Mobile Computing and Networking (MobiCom), Article #1-15, October 2019. ACM Press. DOI 10.1145/3300061.3300120.

Securing the life-cycle of Smart Environments (video)

This one-hour talk by David Kotz was presented at ARM Research in Austin, TX at the end of January 2019.  The first half covers some recent THaW research about Wanda and SNAP and the second half lays out some security challenges in the Internet of Things.  Watch the video below.

Abstract: The homes, offices, and vehicles of tomorrow will be embedded with numerous “Smart Things,” networked with each other and with the Internet. Many of these Things interact with their environment, with other devices, and with human users – and yet most of their communications occur invisibly via wireless networks.  How can users express their intent about which devices should communicate – especially in situations when those devices have never encountered each other before?   We present our work exploring novel combinations of physical proximity and user interaction to ensure user intent in establishing and securing device interactions. 

What happens when an occupant moves out or transfers ownership of her Smart Environment?  How does an occupant identify and decommission all the Things in an environment before she moves out?  How does a new occupant discover, identify, validate, and configure all the Things in the environment he adopts?  When a person moves from smart home to smart office to smart hotel, how is a new environment vetted for safety and security, how are personal settings migrated, and how are they securely deleted on departure?  When the original vendor of a Thing (or the service behind it) disappears, how can that Thing (and its data, and its configuration) be transferred to a new service provider?  What interface can enable lay people to manage these complex challenges, and be assured of their privacy, security, and safety?   We present a list of key research questions to address these important challenges.