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.

Best Poster – MobiCom’18

Tim Pierson’s dissertation work resulted in an innovative method for single-antenna Wi-Fi devices (like many mHealth devices, medical devices, or those in the IoT) to determine with strong confidence whether a Wi-Fi transmitter is close by (within a few centimeters).  This proximity detector can be the basis for trustworthy relationships between devices.   A poster paper about this idea just won the best-poster award at MobiCom 2018, and the full paper was just accepted for presentation at MobiCom 2019. See below for the abstract, or check out the corresponding three-page paper.poster award

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