Cross-Chain Interoperability and Collaboration for Keyword-Based Embedded Smart Contracts in Internet of Things.

In recent years, blockchain technology has been widely applied in the Internet of Things (IoT) field, where devices located in different blockchains need to interact with each other cross-chain. Existing cross-chain models have high implementation complexity, long response times, and are difficult to apply in IoT scenarios. In this paper, we propose keyword-based embedded smart contract cross-chain interoperability and collaboration model. This model identifies the status of smart contracts through the keywords of smart contracts, completes cross-chain operations, and achieves smart contract collaboration and asset exchange among devices in different blockchains. To find matching collaborative contracts, contract-specific keywords will be set, including asset amounts and types. In the cross-chain asset exchange scenario of the model, the assets sent by the sender are frozen in the contract. When the contract is successfully executed, the assets will be sent to the receiver, otherwise returned to the sender. In the cross-chain contract collaboration scenario, we identify the number of contract interactions, and when the contract collaboration is completed, the data will be retained, otherwise it will be invalidated. We also use an embedded smart contract method to further optimize IoT application scenarios. This method embeds the steps of deploying smart contracts into the invoked transaction, enabling the deployment and invocation of smart contracts through a single transaction. The experiments show that the keyword-based embedded contract method is 47% faster and 49% less costly compared to Notary schemes solutions in cross-chain scenarios.