# NetTopoBFT: Network Topology-Aware Byzantine Fault Tolerance for High-Coverage Consortium Blockchains

## TL;DR

NetTopoBFT is a new blockchain consensus algorithm that improves security and performance in large-scale consortium blockchains by considering network topology.

## Contribution

It introduces a topology-aware consensus mechanism with a two-layer node evaluation model and a VRF-based leader selection.

## Key findings

- NetTopoBFT improves consensus node quality while maintaining decentralization.
- The algorithm optimizes communication overhead, security, and network coverage simultaneously.
- Experiments confirm its robustness and connectivity enhancements.

## Abstract

The Practical Byzantine Fault Tolerance (PBFT) algorithm, while fundamental to consortium blockchains, suffers from performance degradation and vulnerability of leader nodes in large-scale scenarios. Existing improvements often prioritize performance while lacking systematic consideration of the structural characteristics of the nodes and network coverage. In this paper, a new network topology-aware Byzantine fault-tolerant algorithm NetTopoBFT is proposed for the supply chain and other application scenarios that require strict transaction finality but moderate throughput. Firstly, it innovatively combines the weighted signed network with the consortium chain, constructs a two-layer Bayesian smoothing node evaluation model, and evaluates the nodes through the two-dimensional evaluation of ‘behavioral reputation plus structural importance’. Then, to reduce the risk of being attacked, it uses Verifiable Random Function (VRF) to decide the leader. Furthermore, it uses a duplicate coverage-driven waitlisting mechanism to enhance the robustness and connectivity of the system. Theoretical analysis and experiment results show that NetTopoBFT significantly improves the quality of consensus nodes under the premise of guaranteeing decentralization, realizes the simultaneous optimization of communication overhead, security and network coverage. It provides a new idea for designing consensus mechanism of consortium blockchains.