Blockchain-based secure communication of internet of things in space-air-ground integrated network

Under the Internet of Things (IoT) era, the cooperation of multiple service providers has facilitated the development of large-scale distributed IoT with a strong demand for reliable and real-time communications. The Space-Air-Ground Integration Network (SAGIN) can be seen as an extension of the traditional terrestrial network with open and ubiquitous connectivity that can be used to support the future IoT in the 6G era. However, the deployment of SAGIN is fraught with numerous challenges, particularly in terms of security. As an emerging technology, blockchain has received academic attention in mitigating the trust problem of SAGIN communication systems. In this paper, we introduce a decentralized data transmission framework that combines the characteristics of SAGIN and blockchain. This framework leverages the increasing computational and communication capabilities of low Earth orbit satellites. Subsequently, we provide an overview of the three-layer structure of this framework and detail the four working steps of the transmission mechanism. Simulation results show that our proposed scheme has excellent performance in terms of latency and throughput while ensuring the security of data transmission.