A Comprehensive Review of Blockchain-Based Access Control and Authentication Mechanisms in IoT-Assisted Smart Healthcare Systems

Abstract

Blockchain is a distributed system that helps to secure data transactions. It is a decentralized design that makes it useful for ensuring safe and scalable communication between the Internet of Things (IoT) devices. Since IoT often depends on remote sharing and data protection, access control becomes a major security concern. Traditional access control methods often difficult to apply in IoT environments because many devices have limited computing power. Researchers have explored how blockchain can strengthen IoT security ever since the technology emerged. In healthcare, for example, conventional e-health systems allow Electronic Health Records (EHRs) to be shared among the providers, but they also create risks such as unauthorized access and data leaks. With IoT, the challenges grow even bigger, managing privacy and concurrency across a large number of lightweight, distributed devices is more complex. Centralized access control system cannot always be trusted to guarantee security in each setting. A systematic survey is presented in this work to review existing approaches used for access control and authentication in IoT-based healthcare environments. Various models, including role-based, attribute-based, and blockchain-based access control models, are analyzed to ensure their effectiveness and scalability. Moreover, cryptographic methods used for authentication purposes in the existing works are explored. Key limitations like high computational overhead, vulnerability to attacks, and lack of standardization in the conventional access control and authentication methods are reviewed. At last, the growing demands and future ideas for implementing secure and highly efficient models for smart healthcare IoT networks are listed.