Abstract: This paper proposes a decision tree Byzantine fault tolerance (DTBFT) algorithm to address the problems of communication overhead, unguaranteed node reputation, and inability to dynamically add or delete nodes in the PBFT algorithm for consortium chains. Firstly, according to the application scenario of the alliance chain, the consensus protocol of the PBFT algorithm is simplified, and the communication overhead is reduced. Secondly, a reputation score mechanism and a decision tree classification algorithm are introduced to improve security of the system. Finally, the selection range of master nodes is narrowed to high-level nodes with good node reputation to prevent frequent view switches. Experiments show that the DTBFT algorithm enhances throughput and algorithm security compared with PBFT.

Key words: blockchain, alliance chain, consensus algorithm, practical Byzantine fault tolerance (PBFT), decision tree classification