A comparative security analysis of MQTT brokers against DoS attacks

The growing use of Internet of Things (IoT) devices has increased the need for secure and reliable communication protocols, with MQTT being one of the most widely used. However, MQTT brokers are vulnerable to denial-of-service (DoS) attacks, which can disrupt data flow in IoT systems. This research compares three MQTT brokers, Mosquitto, HiveMQ, and EMQX, to evaluate their resilience against DoS attacks, specifically the MQTT publish flooding attack. Using a testing environment replicating real-world IoT scenarios, the brokers were subjected to simulated attacks, and their performance was measured based on five key metrics: latency, packet loss, throughput, CPU usage, and recovery time. The results show varying levels of resilience among the brokers. Mosquitto demonstrated quick recovery but suffered from high latency and moderate packet loss. HiveMQ maintained low latency but experienced high packet loss and failed to recover without manual intervention. EMQX balanced performance with the lowest packet loss and a reasonable recovery time, making it the most robust among the three. These findings provide insights into selecting suitable MQTT brokers for IoT deployments, emphasizing the importance of considering factors such as latency, message reliability, and recovery capability when dealing with potential DoS attacks.