Permissionless and Asynchronous Asset Transfer [Technical Report]

TL;DR

This paper introduces Pastro, a permissionless and asynchronous asset transfer system that replaces traditional quorum systems with a weighted Proof-of-Stake mechanism, enabling secure asset transfer without consensus in open environments.

Contribution

It extends asynchronous asset transfer methods from permissioned to permissionless settings using weighted Proof-of-Stake and adaptive adversary tolerance.

Findings

Pastro operates securely in permissionless, asynchronous environments.

It tolerates adaptive adversaries based on asset ownership.

The system improves efficiency by replacing quorum systems with Proof-of-Stake.

Abstract

Most modern asset transfer systems use consensus to maintain a totally ordered chain of transactions. It was recently shown that consensus is not always necessary for implementing asset transfer. More efficient, asynchronous solutions can be built using reliable broadcast instead of consensus. This approach has been originally used in the closed (permissioned) setting. In this paper, we extend it to the open (permissionless) environment. We present Pastro, a permissionless and asynchronous asset-transfer implementation, in which quorum systems, traditionally used in reliable broadcast, are replaced with a weighted Proof-of-Stake mechanism. Pastro tolerates a dynamic adversary that is able to adaptively corrupt participants based on the assets owned by them.