Towards Dependable, Scalable, and Pervasive Distributed Ledgers with Blockchains

Distributed blockchain ledgers are on the verge of becoming a disruptive technology, profoundly impacting a wide range of industries and established applications, such as cryptocurrency, and allowing for novel use cases in both the public sector (e.g., eGovernment, eHealth, etc.) and the private sector (e.g., finance, supply chain management, etc.). Blockchains promise the ability to maintain critical information in a trustworthy repository without any centralized management. The reliability of blockchain-enabled applications is based on the innate immutability of stored data, maintained through cryptographic means, which enables blockchains to provide transparency, efficiency, auditability, trust, and security. As the technology is still in its infancy, a number of pain points must be addressed in order to make distributed ledgers more dependable, scalable, and pervasive. In this paper, we present the research landscape in distributed ledger technology (DLT). To do so, we describe a taxonomy of blockchain applications called blockchain generations. We also present the DCS properties (Decentralization, Consistency, and Scalability) as an analogy to the CAP theorem. Furthermore, we provide a general structure of the blockchain platform which decomposes the distributed ledger into six layers: Application, Modeling, Contract, System, Data, and Network. Finally, we classify research angles across three dimensions: DCS properties impacted, targeted applications, and related layers.