Defense In Depth Research Articles

Development status and challenges of anti-spoofing technology of GNSS/INS integrated navigation

The threat of spoofing interference has posed a severe challenge to the security application of Global Navigation Satellite System (GNSS). It is particularly urgent and critical to carry out in-depth defense research on spoofing interference. When combined with the inertial navigation system (INS), the GNSS/INS integrated navigation system offers distinct advantages in the field of anti-spoofing technology research, which has garnered significant attention in recent years. To summarize the current research achievements of GNSS/INS integrated navigation anti-spoofing technology, it is necessary to provide an overview of the three core technical aspects of spoofing attack principles and implementation strategies, spoofing detection, and spoofing mitigation. First, the principles and implementation strategies of spoofing interference attacks are introduced, and different classifications of spoofing interference attacks are given. Then, the performance characteristics and technical points of different spoofing detection and spoofing mitigation methods are compared and analyzed, and the shortcomings and challenges in the current development of GNSS/INS anti-spoofing technology are pointed out. Finally, based on the summary and shortcomings of the existing technology, a prospect for the future development of GNSS/INS integrated navigation anti-spoofing technology is discussed.

Endpoint cybersecurity: When smart devices turn stupid

With the proliferation of ever-cheaper IoTs (or smart devices) from smart doorbells to WiFi security cameras and baby monitors and hybrid work arrangements involving relaxed BYOD (Bring Your Own Device) policies, cybersecurity education must build awareness on the threats that endpoints pose. While securing corporate networks from cyberattack gains much attention, there is a dearth of educational material that exemplifies the processes by which endpoints are used in hacks, and how to build defenses against endpoint vulnerabilities. This teaching case provides a Defense in Depth (DiD) learning framework on how to defend industrial cyber-physical systems, digital infrastructure and assets. The case illustrates the applicability of a DiD framework independent of attack vector yet particular to endpoint vulnerabilities and shows how lessons from the past can help defend and mitigate future cyberattacks.

NUWARD SMR safety approach and licensing objectives for international deployment

Drawing on the deep experience and understanding of the principles of nuclear safety, as well as many years of nuclear power plant design and operation, the EDF led NUWARD SMR Project is developing a design for a Small Modular Reactor (SMR) of 340 MWe composed of two 170 MWe independent units, that will supplement the offering of high-output nuclear reactors, especially in response to specific needs such as replacement of fossil-fuelled power plants. NUWARD SMR is a mix of proven and innovative design features that will make it more commercially competitive, while integrating safety features that comply with the highest international standards. Following the principles of redundancy and diversity and rigorous application of Defence in Depth (DID), with an international view on nuclear safety licensing, the Project also incorporates new safety approaches into its design development.The NUWARD SMR Project has been in development for a number of years, it entered conceptual design formally in mid-2019 and entered Basic Design in 2023. The objective of the concept design phase was to confirm the project technological choices and to define the first design configuration of the NUWARD SMR product, to document it, in order to launch pre-licensing with the French Safety Authority (ASN) and to define its estimated cost and its subsequent development and construction schedules. As a delivery milestone the Safety Options file (called the Dossier d’Options de Sûreté (DOS)) has been submitted to ASN in July 2023 for their opinion.An integral part of the NUWARD SMR Project, is not only to deliver a design suitable for France and to satisfy French regulation, but to develop a product suitable and indeed desirable, for the international market, with a first focus in Europe. In order to achieve its objectives and realise its market potential, the NUWARD SMR Project needs to define and realise its safety approach within an international environment and that is the key subject of this paper. The following paper:• Summarises the foundation principles and technological background which underpin the design;•Contextualises the key design features with regard to the international safety regulatory framework with particular emphasis on innovative passive safety aspects;•Illustrates the Project activities in preparation for first licensing in France, and also a wider international view via the ASN led Joint Early Review of the NUWARD SMR design, including Finnish and Czech Republic regulators, recently joined by the Swedish, Polish and Dutch regulators;•Articulates the collaborative approach to design development from involvement with the Project partners (the Commissariat à l’énergie atomique et aux énergies alternatives (CEA), Naval Group, TechnicAtome, Framatome and Tractebel) to the establishment of the International NUWARD Advisory Board (INAB), to gain greater international insight and advice;•Concludes with the focus on next steps into detailed design development, standardisation of the design and its simplification to enhance its commercial competitiveness in a context of further harmonisation of the nuclear safety and licensing requirements and aspirations.

Seamless Industry 4.0 Integration: A Multilayered Cyber-Security Framework for Resilient SCADA Deployments in CPPS

The increased connectivity and automation capabilities of Industry 4.0 cyber-physical production systems (CPPS) create significant cyber-security vulnerabilities in supervisory control and data acquisition (SCADA) environments if robust protections are not properly implemented. Legacy industrial control systems and new IP-enabled sensors, instruments, controllers, and appliances often lack basic safeguards like encryption, rigorous access controls, and endpoint security. This exposes manufacturers to substantial risks of cyberattacks that could manipulate, disrupt, or disable critical physical assets and processes related to their production lines and facilities. This study presents a multilayered cybersecurity framework to address these challenges and harden SCADA environments by implementing granular access controls, network micro-segmentation, anomaly detection, encrypted communications, and legacy system upgrades. The multilayered defense-in-depth (DID) approach combines policies, processes, and technologies to counter emerging vulnerabilities. The methodology was implemented in an electronics manufacturing facility across access control, zoning, monitoring, and encryption scenarios. Results show security improvements, including 57.4% fewer unauthorized access events, 41.2% faster threat containment, and 79.2% fewer hacking attempts. The quantified metrics highlight the CPPS resilience and threat mitigation capabilities enabled by the securely designed SCADA architecture, which allows manufacturers to confidently pursue Industry 4.0 integration and digital transformation with minimized disruption.

Did a USB drive disrupt a nuclear program? A Defense in Depth (DiD) teaching case

Defense in Depth (DiD) has become an industry buzzword. But practicing DiD is easier said than done. While cybersecurity researchers have predominantly focused on securing corporate networks, there remains a serious gap in endpoint-threat awareness. Yet endpoint threats were the progenitor of 68% of breaches and hacks in 2019 (Computers Nationwide, 2022), a vulnerability that increased during the COVID-19 lockdown with relaxed BYOD (Bring Your Own Device) policies, more IoTs, and cheaper and larger USB flash drives. This teaching case uses the 2009 Stuxnet attack on Iran’s nuclear facilities to exemplify how a single USB drive was used as an endpoint threat to disrupt a nuclear infrastructure, drawing attention to the need for and how to practice DiD to counter towering complexities ushered in burgeoning endpoints cyberattacks, from hacks to ransomware. The case shows the need for DiD to simultaneously pay heed toward physical, technical, and processual (administrative) measures to prevent, defend, and mitigate cyberattacks, from hacks to ransomware. The case and its teaching notes highlight the opportunities and challenges of practicing DiD for endpoints, from flash drives to IoTs.

Diagnosing core local flow blockages in a VVER-1000/446 reactor using ex-core detectors and neural networks

According to the Defense in Depth (DiD) concept, it is crucially important to detect and mitigate the consequences of accidents in Nuclear Power Plants (NPPs) in the early stages. Due to the nature of local blockages, the timely and suitable detection of melting accidents is a challenging task. Therefore, developing early detection and accurate mechanisms to prevent nuclear accidents as well as mitigation of their consequences are an essential step to be taken into account. In the present study, an add-on system for detecting and monitoring local melting accidents which in the early stages do not lead to SCRAM, is developed using neural networks and neutron ex-core detectors. The results of the core MCNPX model in terms of local flow blockage location in different sub-channels are used as the network training inputs. The core is divided into four, eight, and twenty-four angular segmentations, along with seven radial and ten axial partitions. More than 50,000 local blockage accidents are simulated in the MCNPX code, and 500 networks are trained for achieving an optimal network topology with 90.1% accuracy. The results of trained network shows that the proposed monitoring system is capable of diagnosing local flow blockages in less than one-tenth of a fuel rod height. The sensitivity and noise analysis results can represent the reliability of the designed system considering blockage distances from the detectors. The obtained results demonstrate that by implementing the proposed add-on system, local blockage accidents can be diagnosed with high accuracy.

Performance Analysis of Software-Defined Networks to Mitigate Private VLAN Attacks.

The defence-in-depth (DiD) methodology is a defensive approach usually performed by network administrators to implement secure networks by layering and segmenting them. Typically, segmentation is implemented in the second layer using the standard virtual local area networks (VLANs) or private virtual local area networks (PVLANs). Although defence in depth is usually manageable in small networks, it is not easily scalable to larger environments. Software-defined networks (SDNs) are emerging technologies that can be very helpful when performing network segmentation in such environments. In this work, a corporate networking scenario using PVLANs is emulated in order to carry out a comparative performance analysis on defensive strategies regarding CPU and memory usage, communications delay, packet loss, and power consumption. To do so, a well-known PVLAN attack is executed using simulated attackers located within the corporate network. Then, two mitigation strategies are analysed and compared using the traditional approach involving access control lists (ACLs) and SDNs. The results show the operation of the two mitigation strategies under different network scenarios and demonstrate the better performance of the SDN approach in oversubscribed network designs.

Diverse and Flexible Coping Strategy for Nuclear Safety: Opportunities and Challenges

The concept and methodology of traditional Defense in Depth (DID) was challenged in the Fukushima nuclear accident. In order to fix the weakness of the traditional emergency strategies of nuclear power plants (NPPs) and to enhance the DID for nuclear safety, the U.S. Nuclear Energy Institute (NEI) put forward the concept of Diverse and Flexible Coping Strategies (FLEX) for the special purpose of beyond-design-basis external event (BDBEE) hazard mitigation and the corresponding FLEX support guidelines (FSG). The theory has been wildly spread and accepted by many countries that generate nuclear power. The research on the FLEX strategy is a new trend in nuclear engineering in the recent decade. It provides not only fixed on-site equipment/devices but also on- and off-site portable resources to strengthen the reliability of the nuclear safety system, especially for the disaster/hazards (similar to the Fukushima nuclear accident) triggered by BDBEEs. After a brief introduction of the FLEX strategy, four opportunities and ten challenges are summarized. Subsequently, in view of these challenges and technical difficulties, five suggestions for future work are recommended.

Novel methodology for functional design chain analysis of a nuclear power plant: A new built Finnish power plant case study

Energized by the fact that nuclear power plants (NPP) have a multidisciplinary character as well as a high degree of coupling and interaction between their elements, regulatory bodies worldwide tend to induce a massive number of requirements to ensure the safety of the plants. Mainly, these requirements aim to apply the defence-in-depth (DiD) safety approach. In Fennovoima Hanhikivi 1 (FH1) NPP, the DiD approach is applied through formalizing functional entities that are responsible for defending various DiD levels and preventing them from failure. Each functional entity consists of safety functions that share common non-functional requirements such as safety classification, failure criterion, diversity, and separation requirements.When investigating the safety functions of any NPP, one concludes that they are significantly interconnected and their processing logics exchange a huge number of signals. Therefore, verifying each safety function independently is not effective because a function may seem to perform its function when it is considered alone, but challenges are found when also the interconnected functions are considered. Thus, it becomes essential to verify the whole functional chain. A functional chain can be defined as a set of safety functions that interact together to guarantee the success of plant systems in case of an initiating event. It should be noted that the functional chain term, defined in this study, is different from the safety group term defined in the IAEA safety glossary. The latter is an assembly of equipment, whereas a functional chain is a group of safety functions. In other words, considering the safety engineering process of the plant life cycle, a functional chain is constructed and defined based on plant-level design down to system-level design, while a safety group is constructed based on system-level design.In this study, a methodology for analysing the functional chain is developed. The methodology mainly targets verifying five aspects of the functional chain which are: measurements, actuators, decision-making processing logic, human–machine interface (HMI), and cabling between various components. The methodology utilizes system engineering approach integrated with a relational database that can be utilized to query the plant design data in order to verify the application of non-functional requirements to the plant design components. Additionally, the study also develops a tool that can assist its users to systematically apply the developed methodology and record its results.Finally, a case study for practically applying the methodology to a NPP design is presented. The application of the methodology succeeded in revealing issues that need to be further clarified with the plant supplier. The main usefulness of applying the developed “functional chain analysis” methodology to a NPP is that it provides an additional as-designed verification approach besides the existing verification methods.

Control Systems Cyber Security Reference Architecture (RA) for Critical Infrastructure: Healthcare and Hospital Vertical Example

A reference architecture (RA) provides a common frame of reference with a common vocabulary, reusable designs, and principles that may be applied to future architectures. It can promote re‐use of best practices, improve interoperability, and improve awareness of a system under development of the same mindset. The next version of the Department of Defense (DoD) Chief Information Officer (CIO) Cyber Security Reference Architecture (CSRA) will include an appendix for control systems. It provides a frame of reference for cybersecurity implementations based on generalizations of common principles that can provide a starting point for an organization's architecture effort, inform decision‐making, suggest governance, and help define future policy decisions for control systems. The appendix is based on the outcome of the MOSIACS Joint Capability Technology Demonstration (JCTD), which provides the initial cyber defensive capability framework for integrations of Commercial‐Off‐The‐Shelf (COTS) and Government‐Off‐The‐Shelf (GOTS) components to form a control system cyber defensive solution. The MOSAICS capability was successfully demonstrated in the energy sector critical infrastructure vertical on a power system in August 2021. Its applicability embodied delivery methods for technologies in other essential infrastructure sectors, repeatable playbooks for automated Courses of Action (COA), best practices, and templates for cyber security requirements for control systems. The advantages of the RA are to enable better decision‐making and policy‐making support about cybersecurity for control systems. This paper demonstrates the RA used in the Healthcare and Public Health sector's critical infrastructure vertical to evaluate concepts such as Zero Trust (ZT) and Defense‐in‐Depth (DiD) architecture principles related to policymaking.

Discussion on the Security Mechanism of Energy Internet in 5G network

With the coming of 5G network, it is possible for energy Internet to achieve high bandwidth and low delay interconnection. At the same time, it also brings new security problems. The core elements of 5G - virtualization, cloud migration, network slicing, Internet of Things, 5G gateway and even related software development may become security vulnerabilities. Aiming at the possible security problems in the application of 5G in the energy Internet, including the overall security architecture, industry security subdivision, Internet of Things security operation and maintenance, and the application of new security mechanisms, this paper expounds the relevant concepts and threats. This paper puts forward that in security architecture, we should make full use of security mechanisms such as logical isolation and access control to achieve in-depth defense; in industry segmentation, we should have customized security capability response for different application scenarios of different industries; in the security operation and maintenance of the Internet of Things, we should aim at the complex network environment and topology of mass terminals. In the new security mechanism, it should be combined with large data analysis and AI intelligent processing to enhance the ability of security early warning. Finally, combined with the application scenario of the energy internet, this paper proposes a comprehensive solution to the energy Internet Security in the 5G.

Detection of Visual Similarity Snooping Attacks in Emails using an Extended Client Based Technique

This paper provides an Extended Client Based Technique (ECBT) that performs classification on emails using the Bayessian classifier that attain in-depth defense by performing textual analysis on email messages and attachment extensions to detect and flag snooping emails. The technique was implemented using python 3.6 in a jupyter notebook. An experimental research method on a personal computer was used to validate the developed technique using different metrics. The validation results produced a high acceptable percentage rate based on the four calculated validation metrics indicating that the technique was valid. The cosine of similarity showed a high percentage rate of similarity between the validation labels indicating that there is a high rate of similarity between the known and output message labels. The direction for further study on this paper is to conduct a replica experiments, which enhances the classification and flagging of the snooped emails using an advanced classification method.

A Ring-Based Cybersecurity Architecture for Critical Infrastructure

A defense-in-depth (DID) approach for securing critical information infrastructure has been a common method used in cybersecurity. However, holistic design guidelines are lacking which precludes organizations from adopting them. Therefore, this paper sets out to outline and detail a holistic framework using ring-based nested network zone architecture for the design and implementation of highly secured networked environments. The proposed cybersecurity architecture framework offers a structural design for holistically designed N-tier system architectures. Several implementation options, including zoning perimeters, are suggested as being capable of offering different security capability levels by trading off amongst various security aspects. Also, the proposed architecture allows adaptability in implementations for various real-world networks. This paper also proposes an attack-hops verification approach to evaluate the architectural design.

New safety strategies for nuclear power plants: A review

The Extensive Damage Mitigation Guideline (EDMG), which was developed by the U.S. Nuclear Energy Institute (NEI) owing to the motivation of 911 terrorist attacks and not allowed to spread before the Fukushima nuclear accident, was publicly available after Fukushima nuclear accident and paid attention to worldwide. Many countries have adopted the U.S. EDMG methodology and developed their strategies (some are not called EDMG but have similar functions), planning to introduce it into the emergency plans of their domestic nuclear power plants (NPPs). Based on the defense-in-depth (DID) concept of nuclear safety, the experience of the Fukushima nuclear accident, and the state-of-the-art of EDMGs research, this paper will give a comprehensive review of EDMG. To illustrate the reason for the introduction of EDMG into the traditional NPP procedures/guidelines, the review work started from the perspective of DID in nuclear safety and the reason for the Fukushima nuclear accident from the viewpoint of DID, which showed the weaknesses of DID implementation strategy - underestimation of the damage during a beyond-design-basis external event (BDBEE). EDMG is crucial complementary for the old framework of procedures/guidelines to enhance the concept of DID. The research progress of EDMG in different countries has been reviewed and a rough comparison has been made among them according to the present state-of-the-art from literature. The methodology of EDMG is summarized as follows: (a) Loss of Large Area (LOLA) - the originally designed scenario for EDMG; (b) elements of EDMG - the summarized contents for EDMG implementation; (c) classification of EDMG - initial response EDMGs and Technical Support Center (TSC) response EDMGs; (d) implementation of EDMG-introduction of three phases of EDMG implementation step by step. Furthermore, three typical methods to integrate EDMG into the traditional procedures/guidelines are reviewed. Finally, this paper gives some concluding remarks for EDMG-related critical issues and recommended future work, which may be challenges for the development and application of EDMG and useful for the related researchers. Novelty Statement The studies of the extensive damage mitigation guideline (EDMG), its methodology, and the progress in different countries have been reviewed. Three typical methods to integrate EDMG into the traditional procedures/guidelines are summarized and reviewed. Concluding remarks for EDMG-related critical issues and recommended future work are summarized.

Research on risk prevention and control strategy of power grid CPS system based on intrusion tolerance

In this paper, an information-physical risk prevention and control framework based on intrusion tolerance technology is proposed, which is a multi-stage in-depth defense system for the risk interaction mechanism and evolution process in the power information-physical fusion system, the aim of this paper is to improve the survivability of the system under attack and minimize the loss caused by the risk through multi-phase defense strategy. At the same time, according to the phase characteristics of risk propagation in CPS, a safe operation state transition model considering intrusion tolerance is established. In order to contain the critical failure events in the risk evolution process of the information-physics fusion system, according to the risk development characteristics of the information-physics system under attack, this paper presents a self-organized critical state identification method, which integrates the characteristics of physical network power flow and information network traffic flow, in order to identify the critical nides that make CPS system enter the self-organized critical state under network attack. Finally, according to the characteristics of CPS dependent network structure and the self-organized critical characteristics of risk evolution, the protection strategies of strengthening the protection of key nodes, adjusting the coupling state of dependent edges and adding autonomous nodes are formulated, by considering the decision-making model of risk prevention and control strategy in the game of attack and defense, the current defense resources are reasonably allocated.

Intrusion Detection System Using Data Stream Classification

Secure data communication across networks is always threatened with intrusion and abuse. Network Intrusion Detection System (IDS) is a valuable tool for in-depth defense of computer networks. Most research and applications in the field of intrusion detection systems was built based on analysing the several datasets that contain the attacks types using the classification of batch learning machine. The present study presents the intrusion detection system based on Data Stream Classification. Several data stream algorithms were applied on CICIDS2017 datasets which contain several new types of attacks. The results were evaluated to choose the best algorithm that satisfies high accuracy and low computation time.

A Formal Approach to Network Segmentation

Network segmentation or compartmentalization, and layered protection are two strategies that are critical in building a secure network. In the literature, layered protection has been formalized and termed as the Defence in Depth (DD) strategy. However, network segmentation has been described vaguely, and without any formal approach, thus making the secure design of large networks unwieldy. In this paper, we formally define network segmentation using a formalism based on product family algebra and guarded commands. Then we propose two algorithms that take a set of resources and their access control policies as input and output a robust network topology and the policies of its firewalls. The firewall policies are computed based on the network segmentation formalism and are strategically placed in the network to achieve DD. Further, we use the proposed algorithms to build Software Defined Networks (SDN) and discuss its use in dynamic networks and Internet of Things.

Радикальные исламисты в публикациях центральной прессы в период дагестанской кампании 1999 года

The article examines the image of radical Islamists, which was created in the publications of the largest domestic periodicals during the military operations in Dagestan in August–September 1999. The author analyses front-line reports and interviews with high-ranking military leaders published in such central newspapers and magazines as Nezavisimaya gazeta, Trud, Izvestiya, Kommersant, Echo planety, Novoe vremya and some others. Among the sources, there are both serious analytical broadsheets and tabloids. The author also pays attention to the regional press, for example, the Yaroslavl periodicals Karavan-Ros and Yaroslavskie novosti. These publications delivered valuable information on the ideology of the enemy, their weapons and equipment, and the war crimes they committed, and also reflected the attitude to the militants of the Russian soldiers and policemen who opposed them. The detachments of militants who opposed the federal forces and the Dagestani law enforcement officers appeared in these reports as cruel religious fanatics, intolerant of the bearers of any other ideology, ready to impose it on other people by force. At the same time, following military and law enforcement officials, Russian journalists were forced to recognize high combat qualities of the enemy, their perseverance and steadfastness in battle. Most of the pieces mentioned the fact that the rebels possessed a large number of modern weapons, both domestic and foreign-made, and also said that they had developed professionally competent in-depth defense. The author draws a conclusion about the antipathy of Russian reporters to the rebel combat units and identifies the reasons for the change in the attitude of the media towards them in comparison with the First Chechen War of 1994–96. In those years, journalists condemned military actions of the federal forces in the Caucasus, but in 1999 they supported the operation in Dagestan and considered Islamic radicals as ordinary bandits.

Development of interaction model on the risk assessment method for nuclear facilities using a system model with a multi-layer structure

ABSTRACT After the accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant, in Japan, the scope of the safety regulation requirement was expanded from the level 3 (control of accidents within the design basis) of Defence in Depth (DiD) to the level 4 (measure of severe accidents), and measures related to the level 5 (off-site emergency response) were strengthened. Based on the characteristics of DiD level 4 and 5 measures for accidents of nuclear facilities assuming an earthquake, it is necessary to consider the influence of human operations and the simultaneous occurrence of multiple events. To perform the risk assessment for such accidents, the analysis method that can consider not only the interactions among elements such as system and/or component behaviors and human operations but also the feedback from behaviors of such elements should be needed. However, the conventional Probabilistic Risk Assessment method is insufficient for such considerations because it is a static analysis method. Therefore, the authors introduce a brand-new interaction model that can express the interaction and the feedback using a system model with a multi-layer structure based on both STAMP/STPA method and the system analysis method using Fault Tree Analysis, and propose a risk management process using this model.

Securing IIoT using Defence-in-Depth: Towards an End-to-End secure Industry 4.0

Industry 4.0 uses a subset of the IoT, called Industrial IoT (IIoT) to achieve connectivity, interoperability and decentralisation. The deployment of industrial networks rarely considers security by design, but this becomes imperative in smart manufacturing as connectivity increases. The combination of OT and IT infrastructures in Industry 4.0 adds new security threats beyond those of traditional industrial networks. Defence-in-Depth (DiD) strategies tackle the complexity of this problem by providing multiple defence layers, each of these focusing on a particular set of threats. Additionally, the severe requirements of IIoT networks demand lightweight encryption algorithms. Nevertheless, these ciphers must provide E2E (End-to-End) security, as data pass through intermediate entities, or middleboxes, before reaching its destination. If compromised, middleboxes could expose vulnerable information to potential attackers if it is not encrypted throughout this path. This paper presents an analysis of the most relevant security strategies in Industry 4.0, focusing primarily on DiD. With these in mind, it proposes a combination of DiD, a lightweight E2E encryption algorithm called Attribute-Based-Encryption (ABE) and object security (i.e., OSCORE) to get a full E2E security approach. This analysis is a critical first step to develop more complex and lightweight security frameworks suitable for Industry 4.0.