Z Notation Formalization of Blockchain Healthcare Document Sharing Based on CRBAC

Abstract

Healthcare and business solutions are transforming towards decentralized architectures. In this regard, many blockchain-based solutions have been proposed. Some are order-execute architecture while some are based on the execute-order architecture of blockchain. Execute-order architectures are famous for general purpose business applications. Hyperledger-composer is a smart-contract framework specically designed to model business apps comfortably. Hyperledger-composer supports role-based access control, however, it is new to adopt by Healthcare applications. The most important aspect of Healthcare applications is to provide access to sensitive documents. In this paper, we are formally dening constraint role-based access control (CRBAC) in Z formalization language to prove the properties of CRBAC in a Healthcare document sharing for blockchain, specically for Hyperledger-composer. The paper aims to take Health care document's access via constraint-based access control while the interface to the roles and documents are decentralized.