Distributed Enforcement of Access Control policies in Intelligent Transportation System (ITS) for Situation Awareness

Intelligent Transport Systems (ITS) are crucial to support Situation Awareness (SA), which aims to keep a safe and efficient driving experience. While promising, ITS use for SA brings several security challenges, including enforcing access control policies in distributed environments with stringent computational constraints in terms of availability, consistency, and latency. Consequently, traditional mechanisms used to enforce authorization policies cannot be reused off-the-shelf but need to be carefully adapted to the particular requirements and minimize the overhead of access control enforcement. In this paper, we propose a distributed architecture for access control enforcement for ITS capable of satisfying the requirements of SA scenarios based on the idea of dynamically compiling a high-level specification of access control policies (written in the Attribute-Based Access Control model) into a set of low-level Access Control Lists that are easier to enforce. We discuss how to realize it by reusing well-known techniques developed in the field of distributed systems. To evaluate the applicability of the proposed approach, we build a prototype that we use to conduct an experimental evaluation in the context of two practical use case scenarios.