A Digital Twin Approach for Blockchain Smart Contracts

Digitalization triggered a transformation in our society, leveraging recent innovations introduced by digital tech-nologies to empower real systems with advanced capabilities. Blockchain emerged as a disruptive technology to advance trustless scenarios by enforcing data immutability and change traceability. Deployed in the Blockchain, smart contracts support such transformation, enhancing the application logic toward a trust scenario. Bug in the smart contract can lead to irreversible consequences, producing faulty transactions or unexpected behaviors. Furthermore, the immutable nature of the Blockchain restricts the ability to make updates if unforeseen circumstances or necessary modifications arise. For these reasons, smart con-tracts' continuous inspection and improvement are fundamental to prevent and react to such issues. In this context, Digital Twin is an emerging approach for creating virtual replicas of assets, processes, or systems. By establishing a bi-directional connection, Digital Twin reflects the twinned entity state while simulating its behavior to enable an iterative evolution. In this paper, we propose an approach that exploits Digital Twin capabilities to support dynamic smart contract improvements. By monitoring and analyzing transactions, Digital Twin can suggest possible refinements to the developers by discovering smart contract inconsistencies or deviations from the expected behavior. Those improvements can refer to a change in logic or parameter optimization. These change proposals are then evaluated in the Digital Twin approach, which eventually updates the smart contract on the Blockchain. We assess the feasibility of the proposed approach using a train management application related to the smart transportation domain.