Boosting Byzantine Protocols in Large Sparse Networks with High System Assumption Coverage

TL;DR

This paper introduces a new multi-scale system assumption to develop efficient and reliable Byzantine protocols in large sparse networks, achieving high assumption coverage and improved fault tolerance.

Contribution

It proposes a novel multi-scale adversary model and demonstrates how to construct efficient Byzantine broadcast and agreement protocols under this model.

Findings

Deterministic Byzantine broadcast achieved in logarithmic-degree networks.

Multi-scale adversary allows better trade-offs between assumption coverage and efficiency.

Protocols maintain high reliability even with some low-layer protocol failures.

Abstract

To improve the overall efficiency and reliability of Byzantine protocols in large sparse networks, we propose a new system assumption for developing multi-scale fault-tolerant systems, with which several kinds of multi-scale Byzantine protocols are developed in large sparse networks with high system assumption coverage. By extending the traditional Byzantine adversary to the multi-scale adversaries, it is shown that efficient deterministic Byzantine broadcast and Byzantine agreement can be built in logarithmic-degree networks. Meanwhile, it is shown that the multi-scale adversary can make a finer trade-off between the system assumption coverage and the overall efficiency of the Byzantine protocols, especially when a small portion of the low-layer small-scale protocols are allowed to fail arbitrarily. With this, efficient Byzantine protocols can be built in large sparse networks with high system reliability.