Hierarchical interactions between Ethereum smart contracts across Testnets

Although the primary role of decentralized ledgers, such as blockchains in cryptocurrencies, is to store data related to interactions between users to establish trust within incognizant parties, their capabilities allow them to offer more sophisticated functionalities. Smart contracts are decentralized rules that are stored on the blockchain and are executed on demand. Furthermore, smart contracts can interact with each other via message exchange to access data that are stored on them and to call each others' methods. In this paper, we propose a two-level hierarchical architecture that is composed of two types of smart contracts: custodian and client. A custodian contract can deploy on-demand client contract, access their data and call their methods to perform specific updates. Moreover, we develop a framework to allow client contracts to share common variables among all or partial group of the contracts, which may only be mutated by its creator, custodian contracts. We measure the performance of our proposal by developing the proposed contracts and deploying them on three popular testnets.