VG-Raft: An Improved Byzantine Fault Tolerant Algorithm Based on Raft Algorithm

Permissioned blockchain consensus algorithms can be divided into CFT (Crash Fault Tolerance) algorithms and BFT (Byzantine Fault Tolerance) algorithms [1]. CFT algorithms have better consensus performances while BFT algorithms are better in security due to they can resist Byzantine attacks [2]. Besides, some improved algorithms propose to improve Byzantine fault tolerance and consensus efficiency through techniques such as digital signatures, but they still have some shortcomings in other performances. This paper proposes an improved BFT algorithm VG-Raft (Verification Group Raft). The algorithm introduces the concept of node trust values, and the node cluster selects some nodes with high trust values to form a verification group. Verification group is responsible for checking the consensus process to avoid the error logs being committed to the blockchain. Our simulation results show that VG-Raft has better performances than other BFT algorithms in consensus efficiency, throughput and so on.