Service-Oriented Sharding with Aspen

TL;DR

Aspen is a sharded blockchain protocol that enables secure, scalable, and trust-preserving addition of multiple services on blockchain networks, addressing security, trust, and scalability issues inherent in single-service protocols.

Contribution

The paper introduces Aspen, a novel sharding protocol that allows multiple services to coexist securely on blockchain while maintaining Bitcoin-like trust assumptions.

Findings

Aspen supports secure addition of new services without compromising security.

It scales blockchain capacity with increasing services while preserving trust assumptions.

Aspen handles Byzantine participants and network churn effectively.

Abstract

The rise of blockchain-based cryptocurrencies has led to an explosion of services using distributed ledgers as their underlying infrastructure. However, due to inherently single-service oriented blockchain protocols, such services can bloat the existing ledgers, fail to provide sufficient security, or completely forego the property of trustless auditability. Security concerns, trust restrictions, and scalability limits regarding the resource requirements of users hamper the sustainable development of loosely-coupled services on blockchains. This paper introduces Aspen, a sharded blockchain protocol designed to securely scale with increasing number of services. Aspen shares the same trust model as Bitcoin in a peer-to-peer network that is prone to extreme churn containing Byzantine participants. It enables introduction of new services without compromising the security, leveraging the trust assumptions, or flooding users with irrelevant messages.