Classification of the DLT Consensus Algorithms with Focus on Blockchain

Abstract

The blockchain technology attracted great scientific and applied interest in the last six–seven years. It successfully applies in different areas like fintech, smart cities, IoT, health care, banking, retail, oil industries, and many others. Regardless of the blockchain type (permissioned or permissionless), the data that must be stored in the blockchain network. The algorithm, which is used to “decide” whether to approve (confirm) or not storing the data in the network is the consensus algorithm. It is very important component of the proper blockchain functioning. The author is pursuing two goals with this research. The first one is to make a thorough retrieval of articles from different publishers, based on few keywords, and check if there are any specific trends of research interests in the recent years around these keywords. The second goal is to identify some classifications criteria—like types (public, private, hybrid, and federated), like layers (two layers and multi-layer), etc., and finally, to classify the existing Distributed Ledger Technology (DLT) consensus algorithms with focus on blockchain, based on the architecture and on the access type.