Abstract
Blockchain technology has the potential to revolutionize industries by
offering decentralized, transparent, data provenance, auditable,
reliable, and trustworthy features. However, cross-chain
interoperability is one of the crucial challenges preventing widespread
adoption of blockchain applications. Cross-chain interoperability
represents the ability for one blockchain network to interact and share
data with another blockchain network. Contemporary cross-chain
interoperability solutions are centralized and require re-engineering of
the core blockchain stack to enable inter-communication and data sharing
among heterogeneous blockchain networks. In this paper, we propose an
application-based cross-chain interoperability solution that allows
blockchain networks of any architecture type and industrial focus to
inter-communicate, share data, and make requests. Our solution utilizes
the decentralized applications as a distributed translation layer that
is capable of communicating and understanding multiple blockchain
networks, thereby delegating requests and parameters among them. The
architecture uses incentivized verifier nodes that maintain the
integrity of shared data facilitating them to be readable by the
entities of their network. We define and describe the roles and
requirements of major entities of inter-operating blockchain networks in
the context of healthcare. We present a detailed explanation of the
sequence of interactions needed to share an Electronic Medical Record
(EMR) document from one blockchain network to another along with the
required algorithms. We implement the proposed solution with
Ethereum-based smart contracts for two hospitals and also present cost
and security analysis for the cross-chain interoperability solution. We
make our smart contracts code and testing scripts publicly available.