Block-as-a-Vote: A Framework Scaling Voting-Based Blockchain Consensus Protocols from Single-Model to Multi-Model

Abstract

Blockchain consensus protocols lie at the core of blockchain systems and define how nodes process and finalize block confirmation, provide security guarantees for the system, and meanwhile influence the system performance. Improving the performance of blockchain consensus protocols while ensuring system security is a challenge. Many blockchain consensus protocols, while providing rigorous security guarantees, exhibit low performance. The primary reason is that they process blocks in a serial manner (named single-model), resulting in inefficient utilization of node resources. Nevertheless, one category of blockchain consensus protocols confirms blocks through voting, and they exhibit concurrency in the processing of blocks and votes. In this paper, we propose block-as-a-vote (BaaV), a framework that extends the voting-based blockchain consensus protocols from single-model to multi-model. From the perspective of data structure, the BaaV framework extends the vote into a block that carries data, thus enabling parallel block generation. It allows a block to integrate information from other blocks and votes, thereby achieving batch confirmation of blocks. More importantly, the BaaV framework still restricts votes to voting messages in terms of functionality, and when nodes vote and determine whether a block can be confirmed, they follow the original blockchain consensus protocols, thereby preserving the original security. The BaaV framework can significantly improve the resource utilization of nodes to achieve better performance. In these experiments, the BaaV framework improves the upper bound of node TPS from approximately 2 MB/s to about 6 MB/s, with only a marginal increase in Latency.