SOK: A Comprehensive Survey on Distributed Ledger Technologies

Abstract

In recent years, Blockchain arose as a key technology in building autonomous decentralised financial systems. Its ability to digitize trust enables building trustless systems such as cryptocurrencies where users do not need to rely on any third party to exchange value. The success of cryptocurrencies to operate without any intermediaries draw the interest of business operators who seek to bypass intermediation and thus to reduce cost and gain competitive advantages. As a result, Blockchain was used outside the crypto-sphere to build decentralized systems. However, this portage led to the inception of new types of Blockchains adapted to different specifications and with different designs. Consequently, the technology has diverged from its baseline (Bitcoin) to the point where some systems marketed as "blockchain" share only a few design concepts with the original Blockchain design proposed by Satoshi Nakamoto. This conceptual divergence alongside the lack of comprehensive models and standards made it difficult for both system designers and decision-makers to clearly understand what is a blockchain or to choose a suitable solution.This survey has a double goal; on the one hand, it attempts to contribute to the discussion on the ontological status of DLTs by providing a taxonomy oriented-framework (DCEA) for conceptualizing and examining DLT. On the other hand, it also attempts to present an up-to-date review and evaluation of current blockchains and their variants as constructed of four layers: the data, consensus, execution and application layers.

SoK: A Taxonomy for Critical Analysis of Consensus Mechanisms in Consortium Blockchain

“…Mainstream consortium blockchains and distributed systems [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20] considered in this paper are shown in Table 1 along with their consensus algorithms, use cases areas, and availabilities for smart contract, DApps, open source, and open APIs. From Table 1, a representative list of consensus algorithms used in mainstream consortium blockchains are selected based on their methodologies of achieving consensus.…”

“…The survey of Ferdous et al [19] also missed multiple important protocols. Recently, Bellaj et al [20] provided a comprehensive survey on distributed ledger technologies, but they mainly focused on the network models, not consensus algorithms.…”

Perceptions of Distributed Ledger Technology Key Management - An Interview Study with Finance Professionals

“…Distributed Ledger Technologies (DLTs) describe geographically spread data storage methods that replicate their data through the use of a consensus mechanism. Bellaj et al [13] propose a "taxonomy-oriented framework for conceptualizing and examining DLTs". The most well-known class of DLTs is the blockchain.…”