Adoption of blockchain technology in various realms: Opportunities and challenges

Our society is becoming "smarter" and more interconnected, as evidenced by technological trends such as smart farming, smart healthcare, supply chain and logistics, and smart city and nation. Security and privacy are two major key considerations in these smart applications, such as blockchain-based security solutions for Industry 4.0-based applications (the focus of this study). In this study, we present a systematic review of existing blockchain-based solutions, particularly for Industry 4.0-based applications. We present themerits and demerits of various state-of-the-art approaches. We also highlight the challenges of the blockchain with the scope of interoperability and governance so that this gives a clear understanding to researchers and professionals.