Blockchain state-of-the-art: architecture, use cases, consensus, challenges and opportunities

Blockchain is a chain of blocks where each block contains a set of transactions that are digitally signed by its verifier and stored across the distributed network so that all the legitimate stakeholders can access/verify them. Due to the attributes of Blockchain such as decentralization, immutability, auditability, transparency, and cryptographic security, it offers various benefits to different domains such as cryptocurrency, financial sectors, private/public segments, insurance, healthcare, supply chain management, Internet of Things, etc. However, the technology is in its early stage and still, there is a range of concerns that are yet to be addressed before its wide adoption. Through this paper, we intend to cover extensive study on the Blockchain that includes taxonomy, application/use-cases, consensus mechanisms, prospective research, future directions, and related technologies. This paper also aims to discuss the opportunities, benefits, and challenges of Blockchain technology and to assist the research community in understanding the same.(c) 2021 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).