Towards Cross-Blockchain Smart Contracts
This addresses the need for cross-chain interactions in the heterogeneous blockchain landscape, though it is incremental as it builds on existing technologies.
The paper tackles the problem of limited interoperability between blockchains by introducing a framework that enables smart contracts to be invoked across different blockchains, with evaluation showing performance overheads in time and cost.
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.