VWeiST: A Scalable and Efficient Proof-of-Stake Blockchain Consensus

Abstract

Due to the susceptibility to nothing-at-stake and long-range attacks, the Proof-of-Stake consensus faces challenges in securely and efficiently confirming blocks. We propose a new Proof-of-Stake consensus, Voted Weightest Sub-Tree(VWeiST) consensus. It assigns weights to each block through voting, and nodes confirm blocks by calculating the probability that each block's weight can be exceeded by other competitors. We employ a multi-round voting approach, where a small number of nodes are randomly selected as the committee nodes to vote in each round. This approach results in particularly low communication overhead per block, allowing for scalability to a large number of nodes. Compared to other consensus, our mechanism requires fewer rounds of voting to confirm a block, offering advantages in throughput and transaction latency. In the experiments, VWeiST achieves latency and round reductions down to 40% and 29% of the comparison method's levels at most. Furthermore, we theoretically prove that the consensus ensures liveness and probabilistic safety.