ShieldScatter: Improving IoT Security with Backscatter Assistance

TL;DR

ShieldScatter is a lightweight IoT security system that uses battery-free backscatter tags to create physical-layer signatures, effectively detecting active attacks with minimal energy and hardware costs.

Contribution

It introduces a novel backscatter-assisted approach to enhance IoT security without requiring complex hardware or high energy consumption.

Findings

Mitigates 97% of spoofing attacks with three backscatter tags

Triggers false alarms on only 7% of legitimate traffic

Effective even when attacker is 15 cm away

Abstract

The lightweight protocols and low-power radio technologies open up many opportunities to facilitate Internet-of-Things (IoT) into our daily life, while their minimalist design also makes IoT devices vulnerable to many active attacks due to the lack of sophisticated security protocols. Recent advances advocate the use of an antenna array to extract fine-grained physical-layer signatures to mitigate these active attacks. However, it adds burdens in terms of energy consumption and hardware cost that IoT devices cannot afford. To overcome this predicament, we present ShieldScatter, a lightweight system that attaches battery-free backscatter tags to single-antenna devices to shield the system from active attacks. The key insight of ShieldScatter is to intentionally create multi-path propagation signatures with the careful deployment of backscatter tags. These signatures can be used to construct a sensitive profile to identify the location of the signals' arrival, and thus detect the threat. We prototype ShieldScatter with USRPs and ambient backscatter tags to evaluate our system in various environments. The experimental results show that even when the attacker is located only 15 cm away from the legitimate device, ShieldScatter with merely three backscatter tags can mitigate 97% of spoofing attack attempts while at the same time trigger false alarms on just 7% of legitimate traffic.