Article A Review of Blockchain Architecture and Consensus Protocols: Use Cases, Challenges, and Solutions

Abstract

Over the last decade, blockchain technology has emerged to provide solutions to thecomplexity and privacy challenges of using distributed databases. It reduces cost for customers byeliminating intermediaries and builds trust in peer-to-peer communications. Over this time, theconcept of blockchain has shifted greatly due to its potential in business growth for enterprisesand the rapidly evolving applications in a collaborative smart-city ecosystem, healthcare, andgovernance. Many platforms, with different architectures and consensus protocols, have beenintroduced. Consequently, it becomes challenging for an application developer to choose the rightplatform. Furthermore, blockchain has misaligned with the goals for an efficient green collaborativedigital ecosystem. Therefore, it becomes critical to address this gap and to build new frameworks toalign blockchain with those goals. In this paper, we discuss the evolution of blockchain architectureand consensus protocols, bringing a retrospective analysis and discussing the rationale of theevolution of the various architectures and protocols, as well as capturing the assumptions conduciveto their development and contributions to building collaborative applications. We introduce aclassification of those architectures helping developers to choose a suitable platform for applicationsand providing insights for future research directions in the field to build new frameworks.