CRBFT: An Optimized Blockchain Algorithm for Edge-Based IoT System

In this article, a credit identity ring optimization blockchain algorithm (CRBFT) based on practical Byzantine fault tolerance (PBFT) is proposed to address the security problem for the network of Internet of Things (IoT). The contributions of this work are given as follows. First, combined with the edge computing architecture, CRBFT introduces the improved credit grading protocol and the improved ring signature scheme into the blockchain network, rewards or punishes the nodes through their behavior, changes the way of selecting the primary node, and ensures that the identity of the primary node will not be disclosed, so as to prevent the primary node from adaptive attack by Byzantine nodes, improve the reliability of the nodes participating in the consensus, and enhance the security of the system. Second, in order to reduce the communication traffic among nodes, CRBFT optimizes the consensus protocol, which not only reduces the time complexity of the traffic in the consensus stage from O ( ${n}^{{2}}$ ) to O ( ${n}$ ) but also improves the consensus efficiency of the system while ensuring the system security. Finally, CRBFT aims to measure the performance of CRBFT. This article is simulated and tested in three aspects: throughput (transactions per second), consistency delay, and communication overhead. Performance evaluation shows that CRBFT achieves lower communication overhead than PBFT. When the number of nodes is the same, CRBFT can obtain higher TPS and lower consistency delay. The results show that compared with PBFT, CRBFT can provide very competitive results.