ExClique: An Express Consensus Algorithm for High-Speed Transaction Process in Blockchains

TL;DR

ExClique is a new consensus algorithm that significantly increases transaction processing speed in blockchains by optimizing block broadcasting and eliminating no-turn blocks, outperforming Clique especially in large networks.

Contribution

The paper introduces ExClique, an improved consensus algorithm that reduces communication delays and prevents no-turn blocks, enabling higher transaction throughput in blockchain networks.

Findings

ExClique achieves 2.25x higher TPS in 21-node networks.

ExClique achieves 7.01x higher TPS in 101-node networks.

Experimental results confirm substantial performance improvements over Clique.

Abstract

Proof of Authority (PoA) plays a pivotal role in blockchains for reaching consensus. Clique, which selects consensus nodes to generate blocks with a pre-determined order, is the most popular implementation of PoA due to its low communication overhead and energy consumption. However, our study unveils that the speed to process transactions by Clique is severely restricted by 1) the long communication delay of full blocks (each containing a certain number of transactions) between consensus nodes; and 2) occurrences of no-turn blocks, generated by no-turn nodes if an in-turn block generation fails. Consequently, Clique struggles to support distributed applications requiring a high transaction processing speed, e.g., online gaming. To overcome this deficiency, we propose an Express Clique (ExClique) algorithm by improving Clique from two perspectives: compacting blocks for broadcasting to shorten communication delay and prohibiting the occurrences of no-turn blocks. For performance evaluation, we implement ExClique by modifying Geth of Ethereum, the software implementing Clique, and deploy a permissioned blockchain network by using container technology. The experimental results show that ExClique achieves a substantial enhancement in transactions per second (TPS). Specifically, it boosts TPS by 2.25X in a typical network with 21 consensus nodes and an impressive 7.01X in a large-scale network with 101 consensus nodes when compared to Clique.