MQTT-Chain: an MQTT approach using blockchain and smart contracts to achieve a new Quality of Service level

The proliferation of Internet of Things (IoT) applications has surged in recent years, necessitating efficient communication protocols. The Message Queuing Telemetry Transport (MQTT) protocol, designed specifically for IoT devices, has gained prominence due to its lightweight publisher/subscriber model. However, inherent concerns arise within the conventional MQTT architecture, particularly pertaining to broker-side vulnerabilities. In addressing these concerns and enhancing data security, we advocate the utilization of blockchains and smart contracts for storing and transmitting broker messages. We designed and compared two different approaches, bringing a detailed latency analysis for each step and validating its functional viability, establishing a robust environment for IoT applications.