Towards a Formal Analysis of MQtt Protocol in the Context of Communicating Vehicles

The paper presents a formal approach to model, analyze, and verify a variant of Message Queue Telemetry Transport protocol (MQtt), dedicated to communicating vehicles (MQtt-CV) that send collected data to automotive infrastructures(subscribers). Our formal approach is based on Promela language and its system verification tool, the model checker SPIN. We propose a slight modification of MQtt protocol to reduce the big volume of data collected and sent by vehicles to infrastructures. Indeed, in the original version of MQtt protocol, when a broker receives data from publishers, it sends them directly to its subscribers without any filtration. As consequence, subscribers may be flooded with unimportant data, which increase the problem in the context where infrastructures should manage a huge volume of data sent by thousands of vehicles. So we propose to model and to analyze formally MQtt-CV protocol, to ensure that the components (broker, publisher, subscriber) that implement this protocol interact correctly and fulfill MQtt requirements.