[RZ]In the past decade, blockchain technology has gained popularity in Internet of Things (IoT) systems. A blockchain—as a distributed and immutable ledger secured by strong cryptography algorithms—brings a new perspective to secure IoT systems. [RZ]ManyAlthough many studies have been devoted to integrating blockchain into IoT device management, access control, data integrity, security, and privacy[RZ]. In comparison, the, blockchain-facilitated IoT communication is [RZ]still much less studied. [RZ]Nonetheless, we see the potential of blockchain in decentralizing and securing IoT communicationsBlockchain has great potential in decentralizing and securing IoT communications. [RZ]This paper proposesIn this paper, we propose an innovative IoT service platform powered by the consortium blockchain technology. The [MX]presented solutionproposed platform abstracts machine-to-machine (M2M) and human-to-machine (H2M) communications into services provided by IoT devices. Then, it materializes the data exchange of the IoT network through smart contracts and blockchain transactions. Additionally, we introduce the auxiliary storage layer to the proposed platform to address various [RZ]off-chain data storage [RZ]requirementsneeds. Our proof-of-concept implementation [RZ]iswas tested against various workloads and connection sizes under different block configurations to evaluate the platform’s transaction throughput, latency, and hardware utilization. The experimental results demonstrate that our solution can maintain high performance [RZ]with a throughput of approximately 800 reads per second (RPS), 50–80 transactions per second (TPS), and a latency of 50 ms–2 s under [RZ]most testing scenarioslight to moderate workloads. [RZ]and provide valuable insights on optimizing the blockchain configuration to achieve the best performance.Our extensive evaluation of the performance impact of batch size, batch timeout, and connection size also provides valuable insights into the optimization of blockchain configuration for achieving high performance.