A Secure Communication Protocol Based on Blockchain and MQTT for IOT

Data in the Internet of Things are confronted with security threats such as leakage, tampering, and malicious deletion. Blockchain has the advantages of decentralization and immutability, which can solve the above problems. The MQTT protocol is a lightweight and scalable communication protocol for the application layer of the Internet of Things. Different from the conventional MQTT protocol, this paper proposes a secure authentication MQTT protocol for IoT based on blockchain. It ensures the authenticity and credibility of device and user identities by realizing the decentralized design of MQTT with blockchain’s decentralized authentication mechanism. A smart contract is designed for trusted transactions and data sharing between devices, and a public key encryption algorithm is adopted to encrypt data transmitted between IoT devices. The proposed scheme is proved to achieve secure communication between IoT devices efficiently.