Development of an Advanced Blockchains’ Classification

The current state of blockchain technology development, its key concepts and impact on various branches of economics and science are analyzed. The main stages of the development of blockchain technologies are analyzed both in general and in terms of their security. Particular attention is paid to existing methods of classifying blockchains, their division into public, private and hybrid networks. The most common consensus algorithms, their features and examples of real blockchain projects in which they are used are considered. Based on the research, a generalized classification of blockchains is proposed, which takes into account such key characteristics as the type of access and architecture, the evolution of development, scalability and level of decentralization, and consensus methods. Potential threats to blockchain-based systems are highlighted, including various types of attacks, and their systematization in a graphical form is proposed. The results of the study may be useful for researchers, developers, and analysts working in the field of blockchain technologies, as well as for organizations planning to integrate blockchain into their business processes.