Research and Implementation of Lightweight Security Solutions for IoT MQTT Protocol

Addressing the insufficient built-in security mechanisms of IoT devices using MQTT protocol for communication and the demand for lightweight security solutions, this study proposes a one-to-many secure transmission scheme based on group encryption. The solution adopts a dual optimization strategy: First, it constructs a certificateless public key cryptography system to reduce the computational, communication, and storage burdens caused by traditional certificate management systems. Verification through an MQTT encrypted communication simulation system built on the Ubuntu platform shows that the key generation time of this solution is significantly reduced by 29.8% compared to the SM9 algorithm. Second, this paper introduces the Lagrange interpolation principle to improve the key management mechanism, adopting an interpolation-based key encapsulation and distribution scheme, effectively enhancing the efficiency of group encrypted communication. Simulation results indicate that with the same number of receiving terminals, the complete encrypted communication process time is reduced by an average of 8.98%; with the same amount of encrypted text data, the system time consumption is reduced by an average of 25.3%.