关键词: 区块链, 共识算法, 物联网, 实用拜占庭容错算法, 基本评价指标体系

Abstract: Most of the current consensus algorithms require large computing power or communication environment and are not suitable for resource-constrained Internet of Things (IoT). In view of the limitations of the consensus algorithm in the traditional blockchain applied to the IoT, blockchain consensus algorithms for IoT were reviewed. Firstly, the consensus algorithms for the IoT were summarized and introduced from three categories: improved consensus algorithms based on Practical Byzantine Fault Tolerance (PBFT), improved algorithms based on other consensus algorithms and new blockchain consensus algorithms suitable for the IoT. Secondly, a basic evaluation index system was established to compare consensus algorithms from five aspects: decentralization, scalability, security, delay and energy consumption. Finally, the challenges and future research directions of consensus algorithms for the IoT were analyzed. Analysis of the basic evaluation index system shows that the new blockchain consensus algorithms are more suitable for the IoT than the improved consensus algorithms based on the traditional consensus algorithms. It provides a reference for research on blockchain consensus algorithms for the IoT.

Key words: blockchain, consensus algorithm, Internet of Things (IoT), Practical Byzantine Fault Tolerance (PBFT), basic evaluation index system