Blockchains : Overview , Applications and Challenges

The Blockchain technology has recently attracted increasing interests worldwide because of its potential to disrupt existing businesses and to revolutionize the way applications will be built, operated, consumed and marketed in the near future. While this technology was initially designed as an immutable and distributed ledger for preventing the double spending of cryptocurrencies, it is now foreseen as the core backbone of enterprises by enabling the interoperability and collaboration between organizations. In this context, consortium Blockchains emerged as an interesting architecture concept that benefits from the transactions’ efficiency and privacy of private Blockchains, while leveraging the decentralized governance of public Blockchains. Although many studies have been made on the Blockchain technology in general, the concept of consortium Blockchains has been very little addressed in the literature. To bridge this gap, this article provides a detailed analysis of consortium Blockchains, in terms of architectures, technological components and applications. In particular, the underlying consensus algorithms are analyzed in details, and a general taxonomy is discussed. Then, a practical case study that focuses on the consortium blockchain technology ethermint is performed in order to highlight its main advantages and limitations. Finally, various research challenges and opportunities are discussed. Keywords–Consortium Blockchain; Distributed Ledger Technology; Smart Contract; Consensus Algorithm; Data Privacy and Security; Scalability; Benchmark