Towards a Common Standard Framework for Blockchain Interoperability - A Position Paper

Decentralized ledger technology (DLT) is becoming ubiquitous in today's society.  After an initial grassroots adoption, enterprises embrace this technology, following the opportunity to expand to new businesses - the technology is maturing. However, organizations need to connect their existing systems and processes to blockchains (centralized - decentralized) securely and reliably, sometimes also implying to connect blockchains (decentralized - decentralized). This challenge is known as blockchain interoperability.

Blockchain interoperability comes in three modes: data transfers, asset transfers, and asset exchanges. As blockchain interoperability is still maturing, there are many unsolved challenges across the different interoperability modes. In this \emph{position paper}, we illustrate the remaining challenges of interoperability, focusing on the systematic evaluation of interoperability mechanisms, based on the state of the art and our own experience. We first introduce the notion of cross-chain interoperability and cross-chain rules. Then, we present our survey and results. 

We ran an online survey comprised of 17 items targeting blockchain specialists. Our quantitative analysis shows that several interesting metrics can show promising directions to evaluate integration solutions systematically. Finally, building upon our study, we propose the blockchain interoperability evaluation framework, the first step to evaluate blockchain interoperability solutions systematically.