Asynchronous BFT Asset Transfer: Quasi-Anonymous, Light, and Consensus-Free

TL;DR

This paper presents a novel asynchronous Byzantine-tolerant asset transfer system that is quasi-anonymous, lightweight, and operates without consensus, leveraging cryptographic primitives and a new agreement proof object.

Contribution

It introduces the first asset transfer system combining quasi-anonymity, lightness, and consensus-freedom in an asynchronous Byzantine setting.

Findings

Achieves quasi-anonymity, lightness, and consensus-freedom simultaneously

Uses succinct cryptographic proofs for efficiency

Employs a modular design with a new agreement proof object

Abstract

This paper introduces a new asynchronous Byzantine-tolerant asset transfer system (cryptocurrency) with three noteworthy properties: quasi-anonymity, lightness, and consensus-freedom. Quasi-anonymity means no information is leaked regarding the receivers and amounts of the asset transfers. Lightness means that the underlying cryptographic schemes are \textit{succinct} (\textit{i.e.}, they produce short-sized and quickly verifiable proofs) and each process only stores its own transfers while keeping communication cost as low as possible. Consensus-freedom means the system does not rely on a total order of asset transfers. The proposed algorithm is the first asset transfer system that simultaneously fulfills all these properties in the presence of asynchrony and Byzantine processes. To obtain them, the paper adopts a modular approach combining a new distributed object called ``agreement proof'' and well-known techniques such as commitments, universal accumulators, and zero-knowledge proofs.