Privacy-Preserving Channel Access for Internet of Things

This paper presents a new way of providing privacy for Internet of Things (IoT) in a multi-trust-domain environment. The key idea is to develop a privacy-aware slotted channel access mechanism using which IoT nodes from multiple operators or trust domains can share wireless channel without mutually exposing their identities, thus alleviating threats from cross-trust-domain traffic analysis geared toward node-profiling, link layer topology estimation, node-tracking, and flow-tracking. The proposed scheme uses a novel zero-exposure slot allocation scheme in which packet transmission timing is the only information that is used for scheduling, collision detection, and collision resolution purposes. In addition to the proposed access scheme, this paper reports the design of a custom hardware unit for implementing the proposed protocol in a test-bed of sensors, emulating IoT networks. Presented results include functional validation and performance of the proposed channel access while preventing complete cross-trust-domain identity exposure.