The idea behind this paper is to get closer look and explain the operation of the transaction management system. Increasing the amount of data in the business comes with all the higher requirements for the fast availability of this data. Availability of data today is very questionable even the clouds solutions that are offered in the background are again centralized servers. The paper describes a system that focuses on decentralization, scalability, speed of access, security. Many companies or government institutions are in need for a global data transactional system that can guarantee security. This paper describes one of the global transaction management system and it is called blockchain. Blockchain is a system that can process large amounts of transaction data while maintaining the same processing speed. With its innovative infrastructure, it provides speed, scalability and high availability. This paper describes in detail the functionality and operation of such a system as well as the programming such a system. The program part of the work is written in python programming language and various ready-made python modules are used. To display the user interface code is written by help of various languages: html, css, javascript axios library. An HTTPS protocol is used for communication with the application.