Chain-Net: An Internet-inspired Framework for Interoperable Blockchains

Blockchain has introduced new opportunities with the potential to enhance systems and services across diverse application domains. Fundamental characteristics of blockchains such as immutability, decentralisation, transparency and traceability have a profound role in this. However, integration with contemporary systems and among disparate blockchain-based applications is a non-trivial challenge primarily due to differences with respect to platforms, consensus mechanism, and governance. Although this challenge has received some attention from the research community, it requires careful analysis to analyse existing work and ascertain gaps to achieve effective and efficient solution to this challenge. This article presents a thorough systematic review of existing research within blockchain interoperability highlighting significant contributions. Leveraging this analysis, the article presents an internet-inspired framework (Chain-Net) to facilitate interoperability within blockchain-based systems whereby two systems within independent Blockchain networks can securely exchange data with each other. This is achieved by using gateway module at each network. This module is a lightweight node registered by the Blockchain network, equipped with discovery service to lookup a target blockchain, and is responsible for forwarding cross-chain transactions to gateway module at the target blockchain. Gateway module plays a vital role in the Chain-Net model, as it holds a cross-chain transaction in a pending state until a confirmation is received from the target blockchain, thus maintaining the record integrity between the two chains. The article presents our efforts to evaluate the proposed blockchain interoperability framework against success criteria based on our analysis of the blockchain interoperability challenge.