With the advent of vehicle-to-everything (V2X) communications, many new applications will be enabled, including safety and traffic optimization. However, initial proposals of V2X communication protocols raise privacy concerns about the ability to track vehicles without the owners' consent. While solutions have been proposed to mitigate this tracking, they have focused on a single protocol. We propose a new passive vehicle tracking technique, which we refer to as Vehicle Ensemble Tracking, or VETing. This approach uses traces from secondary radios with long-term identifiers to de-anonymize pseudonyms used by V2X radios. Using a simulator with a network of listeners, we show that VETing can reconstruct high precision paths of vehicles traveling through a city.

This paper is concerned with the high rate realization of finite-state machines. Two new techniques for high rate realization of finite-state machines are presented, one applicable to finite, the other to infinite memory span machines. It is found that any finite-state machine can be realized by a tree of component machines of a proper size with a given high rate, where the propagation delay of the component machine is less than or equal to the reciprocal of the given high rate. For a given set of logic devices, a synthesis procedure for the component machine with a given propagation delay is proposed.