A Review of Distributed Ledger Technologies

Recently the race toward trusted distributed systems has attracted a huge interest, mostly due to the advances in crypto-currencies platforms such as Bitcoin. Currently, different Distributed Ledger Technologies (DLTs) are competing to demonstrate their capabilities and show how they can overcome the limitations faced by others. The common denominator among all distributed ledger technologies is their reliance on a distributed, decentralized peer-to-peer network and a set of modular mechanisms such as cryptographic hashes and consensuses mechanisms. However, their implementations vary substantially in terms of the used data structure, fault tolerance and consensus approaches. This divergence affects the nature of each instance of the DLT in terms of cost, security, latency and performance. In this paper, we present a snapshot of four existing implementations of DLTs. The particularities of each technology and an initial comparison between them is discussed.