Implementation of Smart Contracts Using Hybrid Architectures with On- and Off-Blockchain Components

TL;DR

This paper explores hybrid architectures combining on- and off-blockchain components for smart contracts, addressing limitations of pure blockchain or centralized solutions, and demonstrates a proof of concept on Ethereum.

Contribution

It introduces a novel approach for implementing smart contracts on hybrid architectures, combining on- and off-chain components to improve scalability and trustworthiness.

Findings

Hybrid architecture can effectively support smart contracts with improved QoS.

The proof of concept demonstrates partial execution of smart contracts on off-chain and on-chain components.

The approach addresses scalability and trust issues inherent in pure blockchain or centralized solutions.

Abstract

Recently, decentralised (on-blockchain) platforms have emerged to complement centralised (off-blockchain) platforms for the implementation of automated, digital (smart) contracts. However, neither alternative can individually satisfy the requirements of a large class of applications. On-blockchain platforms suffer from scalability, performance, transaction costs and other limitations. Off-blockchain platforms are afflicted by drawbacks due to their dependence on single trusted third parties. We argue that in several application areas, hybrid platforms composed from the integration of on- and off-blockchain platforms are more able to support smart contracts that deliver the desired quality of service (QoS). Hybrid architectures are largely unexplored. To help cover the gap, in this paper we discuss the implementation of smart contracts on hybrid architectures. As a proof of concept, we show how a smart contract can be split and executed partially on an off-blockchain contract compliance checker and partially on the Rinkeby Ethereum network. To test the solution, we expose it to sequences of contractual operations generated mechanically by a contract validator tool.