International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This paper examines how new security technologies could reshape Bulgaria’s critical infrastructure resilience while simultaneously creating new vulnerabilities and dependencies. Bulgaria’s modernization, pursued through EU and NATO frameworks and supported by initiatives such as the Defense Innovation Center, promises stronger protection against evolving threats. Yet these same pathways embed risks, from reliance on external vendors and standards to design-level weaknesses such as expanded cyber attack surfaces and system complexity. Adopting a prospective, scenario-oriented approach, the paper argues that resilience and dependency develop in parallel, and that anticipating this paradox will be essential for shaping Bulgaria’s future security strategy.

This paper examines the prospective role of Bulgaria’s newly established Defense Innovation Center at Sofia Tech Park in strengthening critical infrastructure resilience. Designed in line with NATO and EU standards, the Center is expected to test emerging technologies and develop prototypes, with an initial focus on unmanned aerial vehicles (UAVs) and advanced defense systems. The analysis adopts a conceptual approach, outlining potential applications of these dual-use technologies across the energy, communications, cyber, and transport sectors. It also highlights key risks, including funding sustainability, dual-use dilemmas, and continued dependence on external technological ecosystems. By situating the initiative within the broader NATO and EU innovation landscape, the paper underscores both the opportunities and uncertainties of integrating defense-driven innovation into national resilience strategies.

This paper examines the integration of artificial intelligence (AI) in airport security, with a particular focus on Sofia Airport within Bulgaria’s critical infrastructure framework. It explores the growing significance of AI in enhancing security protocols at airports, which are critical nodes in national and international transportation networks. The case study highlights a collaborative effort between Sofia Airport and VIP Security, where the “VIP Eye” system was demonstrated to airport officials for testing and feedback. VIP Eye, an AI-driven solution, is designed to detect and mitigate security threats with high precision, featuring capabilities such as weapon detection, masked face recognition, and the identification of physical altercations. The collaboration aimed to refine the system based on insights from Sofia Airport’s security expertise, contributing to advancements in security technology. The study also discusses the broader implications of AI adoption for airport security in Bulgaria, considering both technical advancements and the challenges associated with integrating such technologies within the existing security infrastructure.

There are numerous methodological approaches for modelling, numerical analysis and/or simulation of the behaviour of individual systems. However, modelling the interdependencies between task-oriented or dedicated systems (the so-called system of systems) and describing their complex behaviour, necessarily through simulation, is still an unsolved issue.

This paper explores the pivotal role of technology and innovation in enhancing the resilience of Bulgaria’s critical infrastructure. It examines the integration of advanced technologies such as artificial intelligence, Internet of Things (IoT), blockchain, digital twins, unmanned aerial vehicles (UAVs), cyber-physical systems (CPS), and big data analytics in sectors like hazardous waste management, border security, and airport security. By analyzing case studies and current implementations, the paper highlights the successes and challenges faced in adopting these technologies. The study also discusses the importance of public-private partnerships and regulatory frameworks in fostering an environment conducive to technological innovation. The findings underscore the necessity for continuous investment in technology to safeguard critical infrastructure against emerging threats and to ensure long-term sustainability.

Developing a coordinated and effective response to critical infrastructure (CI) threats, current and anticipated, requires achieving a higher overall level of resilience and protection. The growing interdependence between physical and digital infrastructure creates opportunities for malicious cyberspace actions targeting critical areas to disrupt functionality or damage physical infrastructure. In this regard, through the application of specific approaches to strengthen the resilience of CIs, it is possible to improve the capabilities to counter physical and hybrid threats.
Presenting an option for an effective response agai nst CI threats through the development of security systems is the content of this publication.

The identification and protection of critical infrastructure (CI), which provides essential services for the national and European markets, especially in key sectors of the economy, requires priority measures to be taken to increase its resilience. The concept of resilience is closely related to the ability of a CI to prevent, defend against, respond to, withstand, mitigate and absorb, adapt to, or recover from risk events. Here, both the organizational measures and the technical part of the security systems, developed according to the specifics of CI, play an essential role.
In this regard, this publication presents the framework of the author’s view on the relationship between organizational resilience and CI security.

This article discusses the issues related to the planning of activities for ensuring the physical security of critical infrastructure sites. The critical infrastructure is considered as an important element of the national security of the country, and the cri ticality is determined by the interdependence between the individual elements and the dependence of the society on its normal functioning.

There are numerous methodical approaches to model, numerically analyses or/and simulate single systems’ behavior. However, modeling interdependencies between different systems (so called system-of-systems) and to describe their complex behavior, necessarily by simulation, is still an unresolved issue.

This report studies the threat for the European security posed by terrorist attacks with chemical, biological, nuclear or radiological (CBRN) materials. Latest tendencies of the problem of the last few years are being studied, and some cases broadly discussed in the media worldwide are being analyzed. Terrorists’ methodologies are being assessed, and their possibilities to obtain weapons of mass destruction. The possibility for developing an improvised explosive device with chemical substances aiming to cause damage to critical infrastructure targets which would pose a threat to the national security of the country is also considered.

Integrated management should be seen as synonymous with good management, which means that it is necessary to manage the organization’s activities, resources, personnel, impact on its functioning and countless risks that can cause a lot of problems if it is allowed to be happen than if they being avoided.
The best way to define the parameters of integrated security implies the use of a simple, clear and comprehensive approach and format that allows the senior management of the organization to focus on the key elements that need to be planned, implemented and managed to fulfill the mission of the organization.