Internet of Things (IoT) devices are not only finding increasing use in ordinary households, but they have also become a key element for the Industry 4.0 concept. The implementation of industrial IoT devices into production streamlines the production process and reduces production costs. On the other hand, connected IoT devices bring new security risks to production and expose an industrial environment to new types of attacks. The article analyzes the vulnerability of the production line with implemented industrial IoT devices with consideration of a possible Distributed Denial-of-service (DDoS) attack led by attackers from the internet. Various types of DDoS attacks abusing the presence of IoT devices in the system were performed on an automated production line implementing sorting, preparation, and dosing of bulk and liquid materials for filling into containers. The leading attacks caused failure of the production line during the production, as well as the dysfunction of communication with IoT devices. The article also demonstrates the implementation of countermeasures against DDoS attacks and possible strategies to protect and mitigate such attacks on the production line.

This paper provides heuristic methods for obtaining a burning number, which is a graph parameter measuring the speed of the spread of alarm, information, or contagion. For discrete time steps, the heuristics determine which nodes (centers, hubs, vertices, users) should be alarmed (in other words, burned) and in which order, when afterwards each alarmed node alarms its neighbors in the network at the next time step. The goal is to minimize the number of discrete time steps (i.e., time) it takes for the alarm to reach the entire network, so that all the nodes in the networks are alarmed. The burning number is the minimum number of time steps (i.e., number of centers in a time sequence alarmed “from outside”) the process must take. Since the problem is NP complete, its solution for larger networks or graphs has to use heuristics. The heuristics proposed here were tested on a wide range of networks. The complexity of the heuristics ranges in correspondence to the quality of their solution, but all the proposed methods provided a significantly better solution than the competing heuristic.

The involuntary shutdown at universities during the COVID-19 pandemic and the impossibility of full-time teaching forced university teachers to look for other ways of communication strategies through Internet platforms with students and in everyday academic activities. The aim of this study is to reveal the attitudes and perception of university teachers in the field of Media and Communication Studies in Slovakia during two years of online home learning (2020 and 2021) when the first two waves of the COVID-19 pandemic took place. The aim was to show changes in the perception of the situation in terms of existing positives and negatives during this period as well as to point out a possible trend in the communication strategies used to ensure the sustainability of the education system. Due to the lockdown, the survey was only conducted in electronic format using online questionnaires. The participants were university teachers from the field of Media and Communication Studies. As this is a progressive field the study of which is carried out at the intersection of the interests of several scientific disciplines, it can be assumed that the conclusions can easily be transferred to social, economic, humanities and arts disciplines. When communicating and teaching students in 2020 and also in 2021, online teaching through systems such as Zoom or Google Meet and individual consultations by e-mail, chat and social networks dominated. As the results of the study indicate, modern online technologies contribute to the sustainability of the educational process during an emergency and will become an integral part of university education even after the end of the pandemic situation.

Smart devices along with sensors are gaining in popularity with the promise of making life easier for the owner. As the number of sensors in an Internet of Things (IoT) system grows, a question arises as to whether the transmission between the sensors and the IoT devices is reliable and whether the user receives alerts correctly and in a timely manner. Increased deployment of IoT devices with sensors increases possible safety risks. It is IoT devices that are often misused to create Distributed Denial of Service (DDoS) attacks, which is due to the weak security of IoT devices against misuse. The article looks at the issue from the opposite point of view, when the target of a DDoS attack are IoT devices in a smart home environment. The article examines how IoT devices and the entire smart home will behave if they become victims of a DDoS attack aimed at the smart home from the outside. The question of security was asked in terms of whether a legitimate user can continue to control and receive information from IoT sensors, which is available during normal operation of the smart home. The case study was done both from the point of view of the attack on the central units managing the IoT sensors directly, as well as on the smart-home personal assistant systems, with which the user can control the IoT sensors. The article presents experimental results for individual attacks performed in the case study and demonstrates the resistance of real IoT sensors against DDoS attack. The main novelty of the article is that the implementation of a personal assistant into the smart home environment increases the resistance of the user’s communication with the sensors. This study is a pilot testing the selected sensor sample to show behavior of smart home under DDoS attack.

Today, students live in a world surrounded by technology and traditional education methods are no longer very attractive to them. Applying the concept of a digital educational escape room to teaching can help increase students’ interest in the subject. In an escape room, the players search for clues, complete tasks, and solve polymorphic puzzles, working together to escape the room within a certain time limit. This article presents the use of a digital escape room on third-year students in the field of computer network mechanics at a secondary vocational school. The aim of this study was to determine the effects of implementing an escape room focused on HTML and computer networks on third-year computer network mechanics students and to assess the students’ levels of perception of the game. Although the experiment did not confirm an increase in students’ cognitive abilities, the quantitative analysis confirms a significant increase in the motivation, engagement, and satisfaction of students in secondary vocational schools focusing on technical vocational subjects. Qualitative analysis provides a better understanding of these results and supports the conclusion that using a digital educational escape room is enjoyable for students, and leads to problem-solving skills and teamwork.

The paper presents design, background and experimental results of the IPTables applied in IPv4 and IP6Tables applied in IPv6 network compared through several tested parameters. The experimental testbed environment is based on P2P grid utilized for DDoS attacks. IPTables tool is used for packet filtering and consequently for preventing DoS/DDoS attacks. It allows a system administrator to configure the tables, the chains and rules it stores in order to manage the incoming and outgoing packets. The packets are treated according to the rules’ results provided by the packet processing. A rule in a chain can be bound with another chain in the table etc. We employ the P2P grid environment to carry out as well as to coordinate DDoS attack on the availability of services to simulate real DDoS attack launched indirectly through many compromised computing systems. The same routing protocols as well as the same firewall rules were used for IPv4 and for IPv6 network. The main aim was to analyse pros and cons of new IP6Tables tool compared with IPTables in IPv4 networks in light of the resistance to DDoS attacks which is still one of the most significant threats in the IPv6 networks.