Towards Cross-Blockchain Smart Contracts

TL;DR

This paper introduces a framework enabling cross-blockchain smart contract interactions, supporting recursive calls and continuation across heterogeneous blockchain protocols, with a reference implementation and performance evaluation.

Contribution

It presents the first framework for cross-chain smart contract invocation, including support for recursive calls and continuation, with an Ethereum-based implementation and performance analysis.

Findings

Framework supports cross-chain smart contract invocation

Recursive calls across different blockchains are feasible

Performance overheads are evaluated in terms of time and cost

Abstract

In recent years, manifold blockchain protocols have been proposed by researchers and industrial companies alike. This has led to a very heterogeneous blockchain landscape. Accordingly, it would be desirable if blockchains could interact with each other. However, current blockchain technologies offer only limited support for interoperability, thus preventing tokens or smart contracts from leaving the scope of a particular blockchain. As a first step towards a solution for cross-chain smart contract interactions, we introduce a framework which allows to invoke a smart contract from another blockchain. We offer support for continuing a smart contract after receiving a result from a different blockchain, and for calling smart contracts recursively across blockchains. We provide a reference implementation for Ethereum-based blockchains using Solidity and evaluate the performance regarding time and cost overheads.