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.

翻译：近年来,研究人员和工业公司都提出了多个供应链协议,这导致了一个非常多样化的供应链格局。因此,如果这些供应链能够相互互动,将是可取的。然而,目前的供应链技术只能为互操作性提供有限的支持,从而防止象征性或智能合同离开特定供应链的范围。作为跨链智能合同互动解决方案的第一步,我们引入了一个允许从另一个供应链中援引智能合同的框架。我们支持在从不同的供应链中获取结果后继续签订智能合同,并支持将智能合同传遍整个供应链。我们为基于Eteenum的供应链利用固态提供了参考实施,并评估了时间和成本管理的业绩。