The purpose of this paper is to present the development of a qualitative approach to environmental risk assessment (QAERA) in transport. The approach is described as a model developed for the future software tool which will be utilizable as a risk decision support system. The basic part is aimed on developing a quantitative environmental risk assessment. Thus, this paper describes a set of 6 pillars of safety and security. Accordingly, the paper contains both chosen safety and security indicators and selected criteria for assessing the risk of launching the environmental change of global model thinking in the transport sector. The environmental risk assessment as a global model of thinking was originally based on historical experience but, nowadays, it is changing. Based on new expert knowledge, more precisely, on input of new global data, paper displays an environmental risk assessment with actual interpretation. The discussion of the paper is oriented to support research results, a new knowledge-oriented approach to global climate changes, using suitable risk assessment methods and technics. The result of the paper is a new approach for the modeling of environmental risk assessment in the transport sector.

Thanks to cryptocurrencies, blockchain technology has recently become the focus of interest of both scientists and the public. The paper presents the principles on which blockchain is based and analyzes the possibilities of the application of blockchain technology in more detail. In a part of the analysis, some of the most common cryptocurrencies were considered, such as Bitcoin, Ethereum, USD Coin, Ripple, and ADA. Blockchains' applicability in supply chains, finance, real estate, health care, voting, and smart cities the authors discussed in the chapter about the application of blockchain technology. A separate chapter discusses the limitations of blockchain technology. Based on the analysis, at the end of the paper, the authors conclude that blockchain technology has great potential in automating and optimizing business processes and protecting the information and privacy of users. Given the demonstrated interest of companies in blockchain technology, investments, and demand for staff who understand it and can create applications, the authors concluded that the time of blockchain is yet to come.

SECURITY RISKS FROM THE MODERN MAN-IN-THE-MIDDLE ATTACKS

This paper delves into the significance of hydrogen as a clean energy source, focusing on its properties, production, storage, and distribution. The study highlights the general risks associated with hydrogen usage in various sectors, including hydrogen stations, vehicles, and industrial applications. It presents a comprehensive analysis of hydrogen hazards with safety measures, protocols, and regulations at international, national, and occupational levels. A key section of the paper examines several known hydrogen-related incidents, such as explosions and fires at various facilities and locations worldwide, from the BP Texas City Refinery explosion in 2005 to more recent incidents. Each case study provides an in-depth analysis and extracts valuable lessons learned to improve safety standards and protection measures. The paper explores the future of hydrogen and risk management, emphasizing the development of new technologies and innovative solutions for safer hydrogen use. That includes hydrogen fuel cells coupled with renewable energy sources like wind and solar power to ensure a reliable energy supply and enhance grid stability. By integrating hydrogen as an energy storage medium, the study addresses the intermittent nature of renewable energy sources, ultimately contributing to a more stable and flexible energy system. In conclusion, this paper underscores the importance of continued research and development to mitigate risks, enhance protection measures, and ensure the safe adoption of hydrogen as a sustainable energy solution.

The "smart city" concept is based on the wide use of information and communication technologies. The Internet of Things is the key to the new opportunities to collect and analyze the data needed to create a more pleasant environment. It will connect all the smart-city elements and turn them into a coherent mechanism. Under many definitions, a smart city is a city with good functionality and a perspective on the economy, management, mobility, and environment. At the same time, the city is "sustainable" if it is composed of activities of independent and conscious citizens who can make their own decisions. For the further development of the current smart cities and also the contenders for that title, constant state support for new projects is necessary. After discussing the general criteria for smart cities, the authors considered smart cities in Serbia. Also, they discussed the application of the geographic information system, activities of communal services, eGovernment, and some solutions that are already in use. The authors gave a critical review of shortcomings in practice and inconsistencies in the smart-cities creation in Serbia. They pointed out that the authorities are taking steps toward the digitalization of cities, trying to involve citizens in the decision-making process, realizing that the development of smart cities has a positive impact on the national economy. But also, it must be done more decisively and efficiently, primarily in the field of legislation and project financing.