  Road intersections are widely recognized as a lead cause for accidents and
traffic delays. In a future scenario with a significant adoption of Cooperative
Autonomous Vehicles, solutions based on fully automatic, signage-less
Intersection Control would become viable. Such a solution, however, requires
communication between vehicles and, possibly, the infrastructure over wireless
networks. This increases the attack surface available to a malicious actor,
which could lead to dangerous situations. In this paper, we address the safety
of Intersection Control algorithms, and design a Sliding-Mode-Observer based
solution capable of detecting and estimating false data injection attacks
affecting vehicles' communication. With respect to previous literature, a novel
detection logic with improved detection performances is presented. Simulation
results are provided to show the effectiveness of the proposed approach.
