georgkav

• Kampourakis, Vyron; Kavallieratos, Georgios; Spathoulas, Georgios; Gkioulos, Vasileios & Katsikas, Sokratis (2026). LLM-Assisted AHP for Explainable Cyber Range Evaluation. In Esnoul, Coralie & Simensen, John Eidar (Ed.), EnCyCriS '26: Proceedings of the 2026 ACM/IEEE 7th International Workshop on Engineering and Cybersecurity of Critical Systems. Association for Computing Machinery (ACM). ISSN 9798400723926. p. 26–33. doi: 10.1145/3786160.3788467. Full text in Research Archive Show summary

  Cyber Ranges (CRs) have emerged as prominent platforms for cybersecurity training and education, especially for Critical Infrastructure (CI) sectors that face rising cyber threats. One way to address these threats is through hands-on exercises that bridge IT and OT domains to improve defensive readiness. However, consistently evaluating whether a CR platform is suitable and effective remains a challenge. This paper proposes an evaluation framework for CRs, emphasizing mission-critical settings by using a multi-criteria decision-making approach. We define a set of evaluation criteria that capture technical fidelity, training and assessment capabilities, scalability, usability, and other relevant factors. To weight and aggregate these criteria, we employ the Analytic Hierarchy Process (AHP), supported by a simulated panel of multidisciplinary experts implemented through a Large Language Model (LLM). This LLM-assisted expert reasoning enables consistent and reproducible pairwise comparisons across criteria without requiring direct expert convening. The framework’s output equals quantitative scores that facilitate objective comparison of CR platforms and highlight areas for improvement. Overall, this work lays the foundation for a standardized and explainable evaluation methodology to guide both providers and end-users of CRs.

• Takaronis, Michail; Gkioulos, Vasileios; Kavallieratos, Georgios & Lin, Jia-Chun (2026). Applying SOA Principles to Next-Generation Cyber Range Design | Springer Nature Link. In D'Arco, Paolo & Zamfiroiu, Alin (Ed.), Innovative Security Solutions for Information Technology and Communications 18th International Conference, SecITC 2025, Bucharest, Romania, November 20–21, 2025, Revised Selected Papers. Springer. ISSN 9783032174437. p. 278–292. doi: 10.1007/978-3-032-17443-7_17. Full text in Research Archive Show summary

  Cyber ranges (CRs) are interactive platforms that simulate networks, systems, and attack-defense exercises, along with security testbeds and cyber-physical ranges. The latter systems are preferred for cyber-physical systems scenarios due to the variety of heavyweight...

• Kampourakis, Konstantinos; Gkioulos, Vasileios; Kavallieratos, Georgios & Lin, Jia-Chun (2025). Digital Twin-Enabled Incident Detection and Response: A Systematic Review of Critical Infrastructures Applications. International Journal of Information Security. ISSN 1615-5262. 24(5). doi: 10.1007/s10207-025-01113-0. Full text in Research Archive Show summary

  Abstract The escalating digital interconnectivity of Critical Infrastructure (CI) necessitates robust cybersecurity solutions, particularly for effective incident detection and response. This systematic literature review explores the promising role of Digital Twins (DTs) in enhancing these critical functions across diverse CI sectors, including smart cities, healthcare, and energy. Covering research from 2019 onwards, we conduct an in-depth analysis of 27 curated articles, examining attacks, detection methods, response techniques, and emerging trends specifically related to incident handling within this domain. Our review reveals DTs as a powerful tool for CI cybersecurity, enabling proactive threat simulation and improved incident management capabilities. However, challenges persist, including scalability, interoperability with legacy systems, and the need for rigorous real-world validation of incident response effectiveness. Furthermore, we identify common shortcomings in existing research, such as algorithmic flaws, inadequate validation, poor metric reporting, and insufficient threat modeling, all of which impact incident-handling capabilities. Despite these limitations, our systematic analysis underscores that DTs can significantly bolster CI security for incident detection and response when these challenges are addressed. To our knowledge, this work provides the first full-fledged survey uniquely and specifically focused on DT-enabled cybersecurity incident detection and response within CI contexts, addressing a critical gap not comprehensively covered by prior reviews and serving as a foundational resource for stakeholders.

• Kampourakis, Vyron; Kavallieratos, Georgios; Gkioulos, Vasileios & Katsikas, Sokratis (2025). Cracks in the chain: A technical analysis of real-life supply chain security incidents. Computers & Security. ISSN 0167-4048. 159. doi: 10.1016/j.cose.2025.104673. Full text in Research Archive Show summary

  As Industry 5.0 drives greater digitalization and interconnectivity, supply chains have become vital to global commerce, ensuring the seamless flow of goods, services, and data. However, this reliance has also swelled the attack surface, rendering supply chains a prime target for evildoers. Meanwhile, the inherent complexity of supply chain ecosystems prevents defenders from fully applying contemporary security controls promptly and effectively. Clearly, the combination of these hindering factors has led to some of the most severe cybersecurity incidents of the past years. This study is the first to our knowledge that undertakes a comprehensive technical analysis of reported supply chain security incidents. Our analysis is done both from offensive and defensive prisms, leveraging well-established cybersecurity frameworks and guidelines, namely, the ATT&CK MITRE knowledge base matrix and the NIST SP 800-161, respectively. Furthermore, to consolidate our findings and facilitate future research initiatives, we compiled a fundamental dataset that can be used as the basis for automated analysis and potential integration with cybersecurity workflows. The key observations of a 33-incident analysis through the lens of an ATT&CK MITRE- and NIST SP 800-161-based taxonomies we propose can be wrapped up into two key points. First, the attack surface continues to expand, following an upward spiral due to the mushrooming of tactics and techniques that can facilitate the early or late stages of attacks, highlighting their complexity, sophistication, and widespread impact. Second, our findings underscore the necessity of a multifaceted approach to strengthening supply chain resilience. This includes implementing robust cybersecurity controls, comprehensive risk assessment methodologies, and transparent collaboration among suppliers, customers, and vendors to ensure adherence to state-of-the-art cybersecurity best practices.

• Oruc, Aybars; Kavallieratos, Georgios; Gkioulos, Vasileios & Katsikas, Sokratis (2025). Perspectives on the Cybersecurity of the Integrated Navigation System. Journal of Marine Science and Engineering (JMSE). 13(6). doi: 10.3390/jmse13061087. Full text in Research Archive
• Utsash, Masrur Masqub; Kavallieratos, Georgios; Antonakopoulos, Konstantinos & Katsikas, Sokratis (2025). Investigating the Effectiveness of Zero–Trust Architecture for Satellite Cybersecurity. In Pietro, Roberto Di; Renaud, Karen & Mori, Paolo (Ed.), Proceedings of the 11th International Conference on Information Systems Security and Privacy - (Volume 2). SciTePress. ISSN 9789897587351. p. 133–140. doi: 10.5220/0013103200003899. Full text in Research Archive
• Kavallieratos, Georgios; Amro, Ahmed Walid; Gkioulos, Vasileios; Stamatescu, Grigore; Rantos, Kostantinos & Lagkas, Thomas [Show all 12 contributors for this article] (2025). Best-Practices-Based Training for Improving Cybersecurity in Power Grids. In Garcia-Alfaro, Joaquin; Barker, Ken; Navarro-Arribas, Guillermo; Pérez-Solà, Cristina; Delgado-Segura, Sergi; Katsikas, Sokratis; Cuppens, Frédéric; Lambrinoudakis, Costas; Cuppens-Boulahia, Nora; Pawlicki, Marek & Choraś, Michał (Ed.), Computer Security. ESORICS 2024 International Workshops: DPM, CBT, CyberICPS, Bydgoszcz, Poland, September 16–20, 2024, Revised Selected Papers, Part I. Springer. ISSN 9783031823497. doi: 10.1007/978-3-031-82362-6_21. Full text in Research Archive
• Frøseth, Even Kvam; Kavallieratos, Georgios & Katsikas, Sokratis (2025). Threat Modeling in Satellite Communications for Maritime Operations. In Garcia-Alfaro, Joaquin; Barker, Ken; Navarro-Arribas, Guillermo; Pérez-Solà, Cristina; Delgado-Segura, Sergi; Katsikas, Sokratis; Cuppens, Frédéric; Lambrinoudakis, Costas; Cuppens-Boulahia, Nora; Pawlicki, Marek & Choraś, Michał (Ed.), Computer Security. ESORICS 2024 International Workshops: DPM, CBT, CyberICPS, Bydgoszcz, Poland, September 16–20, 2024, Revised Selected Papers, Part I. Springer. ISSN 9783031823497. p. 403–424. doi: 10.1007/978-3-031-82349-7_26. Full text in Research Archive
• Vatn, Karl Jonatan Due; Kavallieratos, Georgios & Katsikas, Sokratis (2024). Threat analysis in Dairy Farming 4.0, Computer Security. ESORICS 2023 International Workshops. Springer. ISSN 9783031542039. p. 46–63. doi: 10.1007/978-3-031-54204-6_3. Full text in Research Archive
• Katsikas, Sokratis; Kavallieratos, Georgios & Amro, Ahmed Walid (2024). Future Trends in Maritime Cybersecurity, Computer and Information Security Handbook (2-Volume Set). Elsevier. ISSN 9780443132230. p. 1663–1678. doi: 10.1016/B978-0-443-13223-0.00104-1. Full text in Research Archive Show summary

  This chapter provides an overview of the current state of cybersecurity in the maritime sector. It examines the factors of change in the maritime sector in regard to cybersecurity, explores the sector's responses to these factors through the introduction and adoption of cybersecurity solutions and strategies, and offers insights into the expected directions and emerging trends that will increase the cybersecurity posture in this sector. The digital transformation in the maritime sector, vulnerabilities, cyber attacks, and policies are examined as the key factors of change. Further, the cybersecurity solutions and approaches are discussed toward identifying the future directions and trends in the maritime sectors. Although the maritime sector is responding to the rising demands for cybersecurity, maritime cybersecurity is a growing field of study, and several directions and research paths need to be explored.

• Moen, Ivar Olav; Oruc, Aybars; Amro, Ahmed Walid; Gkioulos, Vasileios & Kavallieratos, Georgios (2024). Survey-based analysis of cybersecurity awareness of Turkish seafarers. International Journal of Information Security. ISSN 1615-5262. 23. doi: 10.1007/s10207-024-00884-2. Full text in Research Archive Show summary

  In recent years, vessels have become increasingly digitized, reflecting broader societal trends. As a result, maritime operations have become an attractive target for cyber threat actors. Despite the limited cybersecurity training seafarers receive, they are expected to operate within technologically advanced environments. The importance of cybersecurity awareness is evident, but the extent of seafarers’ knowledge in this area remains uncertain. This article investigates three primary aspects: (1) the current state of cybersecurity onboard cargo vessels, (2) seafarers’ cybersecurity awareness, and (3) potential improvements in seafarers’ cybersecurity awareness. To accomplish this, a literature review is conducted to collect and analyze current research, supplemented by a questionnaire survey targeting Turkish seafarers. Our findings support increased investment in awareness and training programs, including organizational-wide cybersecurity awareness efforts, more frequent training, mandatory training for all seafarers through the Standards of Training Certification and Watchkeeping (STCW), and the appointment of a cybersecurity Officer (CySO) to ensure satisfactory cybersecurity levels onboard. Since this article focuses on high-level topics by assessing the general state of maritime cybersecurity and seafarers’ cybersecurity awareness, it does not delve into detailed considerations of awareness and training programs. Nevertheless, it lays the foundation for future research in this area.

• Kavallieratos, Georgios & Katsikas, Sokratis (2023). An exploratory analysis of the last frontier: A systematic literature review of cybersecurity in space. International Journal of Critical Infrastructure Protection. ISSN 1874-5482. 43(December 2023). doi: 10.1016/j.ijcip.2023.100640. Full text in Research Archive Show summary

  Nowadays, assets in space are vital for the provision of critical societal functions such as transportation, communication, production and supply of food, agriculture, etc. The increasing adoption of services provided by assets in space in our every day life, as well as the high dependence on cyberphysical systems, the increased interconnection and the commercialization of space increase the attack surface and poses significant cybersecurity risks to the space infrastructure; several cybersecurity incidents have already threatened assets in space. This work systematically reviews existing studies on the cybersecurity of the space infrastructure, analyzes the main results of each work, organizes and systematizes the current knowledge in the field, and proposes future research directions towards improving the cybersecurity posture of assets in space.

• Oruc, Aybars; Kavallieratos, Georgios; Gkioulos, Vasileios & Katsikas, Sokratis (2023). Cyber Risk Assessment For Ships (CRASH). TransNav, International Journal on Marine Navigation and Safety of Sea Transportation. ISSN 2083-6473. 18(1), p. 115–124. doi: 10.12716/1001.18.01.10. Full text in Research Archive
• Kavallieratos, Georgios & Katsikas, Sokratis (2023). Speed 2 Comes True: Cyberattacks against Ships. In Ferrag, Mohamed Amine; Kantzavelou, Ioanna; Maglaras, Leandros & Janicke, Helge (Ed.), Hybrid Threats, Cyberterrorism and Cyberwarfare. CRC Press. ISSN 9781003314721. Full text in Research Archive
• Spathoulas, Georgios; Kavallieratos, Georgios; Katsikas, Sokratis & Baiocco, Alessio (2022). Attack Path Analysis and Cost-Efficient Selection of Cybersecurity Controls for Complex Cyberphysical Systems. In Katsikas, Sokratis; Lambrinoudakis, Costas; Cuppens, Nora; mylopoulos, John; Kalloniatis, Christos; Meng, Weizhi; Furnell, Steven; Pallas, Frank; Pohle, Jörg; Sasse, Angela; Abie, Habtamu; Ranise, Silvio; Verderame, Luca; Cambiaso, Enrico; Vidal, Jorge Maestre & Monge, Marco Antonio Sotelo (Ed.), Computer Security. ESORICS 2021 International Workshops CyberICPS, SECPRE, ADIoT, SPOSE, CPS4CIP, and CDT&SECOMANE, Darmstadt, Germany, October 4–8, 2021, Revised Selected Papers. Springer. ISSN 9783030954833. p. 74–90. doi: 10.1007/978-3-030-95484-0_5. Full text in Research Archive Show summary

  The increasing integration of information technology with operational technology leads to the formation of Cyber-Physical Systems (CPSs) that intertwine physical and cyber components and connect to each other. This interconnection enables the offering of functionality beyond the combined offering of each individual component, but at the same time increases the cyber risk of the overall system, as such risk propagates between and aggregates at component systems. The complexity of the resulting systems in many cases leads to difficulty in analyzing cyber risk. Additionally, the selection of cybersecurity controls that will effectively and efficiently treat the cyber risk is commonly performed manually, or at best with limited automated decision support. In this paper, we extend our previous work in [1] to analyze attack paths between CPSs on one hand, and we improve the method proposed therein for selecting a set of security controls that minimizes both the residual risk and the cost of implementation. We use the DELTA demand-response management platform for the energy market stakeholders such as Aggregators and Retailers [2] as a use case to illustrate the workings of the proposed approaches. The results are sets of cybersecurity controls applied to those components of the overall system that have been identified to lie in those attack paths that have been identified as most critical among all the identified attack paths.

• Kavallieratos, Georgios; Grigoriadis, Christos; Katsika, Angeliki; Spathoulas, Georgios; Kotzanikolaou, Panayiotis & Katsikas, Sokratis (2022). Risk assessment and control selection for cyber-physical systems: A case study on supply chain tracking systems. Journal of Surveillance, Security and Safety (JSSS). 3. doi: 10.20517/jsss.2022.17. Full text in Research Archive Show summary

  Aim: The paper proposes a novel risk assessment method ology for complex cyber-physical systems: The proposed method ology may assist risk assessors to: (a) assess the risks deriving from cyber and physical interactions among cyber-physical components; and (b) prioritize the control selection process for mitigating these risks. Methods: To achieve this, we combine and modify appropriately two recent risk assessment method ologies targeted to cyber physical systems and interactions, as underlying building blocks. By applying the existing method ology, we enable the utilization of well-known software vulnerability taxonomies, to extract vulnerability and impact submetrics for all the interactions among the system components. These metrics are then fed to the risk analysis phase in order to assess the overall cyber-physical risks and to prioritize the list of potential mitigation controls. Results: To validate the applicability and efficiency of the proposed method ology, we apply it in a realistic scenario involving supply chain tracking systems. Conclusion: Our results show that the proposed method ology can be effectively applied to capture the risks deriving from cyber and physical interactions among system components in realistic application scenarios, while for large scale networks further testing should be carried out.

• Kavallieratos, Georgios; Spathoulas, Georgios & Katsikas, Sokratis (2021). Cyber Risk Propagation and Optimal Selection of Cybersecurity Controls for Complex Cyberphysical Systems. Sensors. 21(5). doi: 10.3390/s21051691. Full text in Research Archive Show summary

  The increasingly witnessed integration of information technology with operational technology leads to the formation of Cyber-Physical Systems (CPSs) that intertwine physical and cyber components and connect to each other to form systems-of-systems. This interconnection enables the offering of functionality beyond the combined offering of each individual component, but at the same time increases the cyber risk of the overall system, as such risk propagates between and aggregates at component systems. The complexity of the resulting systems-of-systems in many cases leads to difficulty in analyzing cyber risk. Additionally, the selection of cybersecurity controls that will effectively and efficiently treat the cyber risk is commonly performed manually, or at best with limited automated decision support. In this work, we propose a method for analyzing risk propagation and aggregation in complex CPSs utilizing the results of risk assessments of their individual constituents. Additionally, we propose a method employing evolutionary programming for automating the selection of an optimal set of cybersecurity controls out of a list of available controls, that will minimize the residual risk and the cost associated with the implementation of these measures. We illustrate the workings of the proposed methods by applying them to the navigational systems of two variants of the Cyber-Enabled Ship (C-ES), namely the autonomous ship and the remotely controlled ship. The results are sets of cybersecurity controls applied to those components of the overall system that have been identified in previous studies as the most vulnerable ones; such controls minimize the residual risk, while also minimizing the cost of implementation.

• Kavallieratos, Georgios & Katsikas, Sokratis (2020). Managing Cyber Security Risks of the Cyber-Enabled Ship. Journal of Marine Science and Engineering (JMSE). 8(10). doi: 10.3390/jmse8100768. Full text in Research Archive Show summary

  One aspect of the digital transformation process in the shipping industry, a process often referred to as Shipping 4.0, is the increased digitization of on board systems that goes along with increased automation in and autonomy of the vessel. This is happening by integrating Information Technology with Operation Technology systems that results in Cyber Physical Systems on which the safe operations and sailing of contemporary and future vessels depend. Unavoidably, such highly interconnected and interdependent systems increase the exposure of the vessel’s digital infrastructure to cyber attacks and cyber security risks. In this paper, we leverage the STRIDE and DREAD methodologies to qualitatively and quantitatively assess the cyber risk of Cyber Physical Systems on board digitalized contemporary and future ships. Further, we propose appropriate cyber security baseline controls to mitigate such risks, by applying a systematic approach using a set of criteria that take into account the security requirements; the cyber risks; the possible attacks; and the possibly already existing controls, to select from the list of controls provided in the Industrial Control Systems (ICS) overlay of the NIST Guide to ICS Security. The results are expected to support the decision-making and the design of a security architecture for the cyber-enabled ship.

• Kavallieratos, Georgios; Katsikas, Sokratis & Gkioulos, Vasileios (2020). Modelling Shipping 4.0: A Reference Architecture for the Cyber-Enabled Ship. In Nguyen, Ngoc Thanh; Jearanaitanakij, Kietikul; Semalat, Ali; Trawiński, Bogdan & Chittayasothorn, Suphamit (Ed.), Intelligent Information and Database Systems, 12th Asian Conference, ACIIDS 2020, Phuket, Thailand, March 23–26, 2020, Proceedings, Part II. Springer Nature. ISSN 9783030420581. p. 202–217. doi: 10.1007/978-3-030-42058-1_17. Full text in Research Archive Show summary

  There is intense activity of the maritime industry towards making remotely controlled and autonomous ships sail in the near future; this activity constitutes the instantiation of the Industry 4.0 process in the maritime industry. Yet, a reference model of the architecture of such vessels that will facilitate the “shipping 4.0” process has not yet been defined. In this paper we extend the existing Maritime Architectural Framework to allow the description of the cyber-enabled ships (C-ESs), and we demonstrate the use of the extended framework by developing descriptions of the architecture of variants of the Cyber-enabled ship. The results can be used not only to systematically describe the architecture of Cyber-enabled ships in a harmonized manner, but also to identify standardization gaps, and to elicit the cybersecurity requirements of the C-ES ecosystem.

• Kavallieratos, Georgios & Katsikas, Sokratis (2020). Attack Path Analysis for Cyber Physical Systems. In Katsikas, Sokratis; Cuppens, Frédéric; Cuppens, Nora; Lambrinoudakis, Costas; Kalloniatis, Christos; Mylopoulos, John; Antón, Annie; Gritzalis, Stefanos; Meng, Weizhi & Furnell, Steven (Ed.), Computer Security: ESORICS 2020 International Workshops, CyberICPS, SECPRE, and ADIoT, Guildford, UK, September 14–18, 2020, Revised Selected Papers. Springer Publishing Company. ISSN 9783030643300. p. 19–33. doi: 10.1007/978-3-030-64330-0_2. Full text in Research Archive Show summary

  The identification and analysis of potential paths that an adversary may exploit to attack Cyber Physical Systems comprising sub-systems enables the comprehensive understanding of the attacks and the impact that may have to the overall system, thus facilitating the definition of appropriate countermeasures that will satisfy the pertinent security requirements. To this end, several attack modelling techniques can be employed, the attack graph being the most prevalent among them. Unfortunately, the discovery and analysis of all possible attack paths in an attack graph is not possible in systems even of a moderate size. In this work we propose a novel systematic method for discovering and analyzing attack paths in real-world scale interconnected Cyber Physical Systems. The method considers the criticality of each sub-system in discovering paths and the risk to the overall system that each path presents to analyze and prioritize paths. We illustrate the workings of the method by applying to the navigational Cyber Physical Systems of the Cyber-Enabled Ship to identify and analyze highly critical attack paths originating from the Automatic Identification System (AIS) and targeting the Autonomous Navigation System (ANS).

• Kavallieratos, Georgios; Katsikas, Sokratis & Gkioulos, Vasileios (2020). SafeSec Tropos: Joint security and safety requirements elicitation. Computer Standards & Interfaces. ISSN 0920-5489. 70:103429, p. 1–11. doi: 10.1016/j.csi.2020.103429. Full text in Research Archive Show summary

  The growing convergence of information technology with operational technology and the accordant proliferation of interconnected cyber-physical systems (CPSs) has given rise to several security and safety challenges. One of these refers to systematically identifying coherent, consistent, and non-conflicting security and safety requirements. This paper proposes an integrated method for safety and security requirements engineering for CPSs at the design stage of the system lifecycle. The method identifies security and safety objectives, it systematically elicits a comprehensive list of requirements, and it links these requirements to objectives, thus facilitating the process of resolving conflicts. To provide insight into the operations of the method, we demonstrate its use to the most vulnerable CPSs on board the Cyber-Enabled Ship (C-ES). By utilizing the proposed method, the safety and security objectives of these systems were defined, and their safety and security requirements were identified.

• Kavallieratos, Georgios; Katsikas, Sokratis & Gkioulos, Vasileios (2020). Cybersecurity and Safety Co-Engineering of Cyberphysical Systems—A Comprehensive Survey. Future Internet. 12(4). doi: 10.3390/fi12040065. Full text in Research Archive Show summary

  Safeguarding both safety and cybersecurity is paramount to the smooth and trustworthy operation of contemporary cyber physical systems, many of which support critical functions and services. As safety and security have been known to be interdependent, they need to be jointly considered in such systems. As a result, various approaches have been proposed to address safety and cybersecurity co-engineering in cyber physical systems. This paper provides a comprehensive survey of safety and cybersecurity co-engineering methods, and discusses relevant open issues and research challenges. Despite the extent of the existing literature, several aspects of the subject still remain to be fully addressed.

• Amro, Ahmed Walid; Kavallieratos, Georgios; Louzis, Konstantinos & Thieme, Christoph Alexander (2020). Impact of cyber risk on the safety of the MilliAmpere2 Autonomous Passenger Ship. IOP Conference Series: Materials Science and Engineering. ISSN 1757-8981. 929. doi: 10.1088/1757-899X/929/1/012018. Full text in Research Archive Show summary

  The digitalization of the maritime sector is continuously growing, leading to increased automation, such as, the development of autonomous vessels. The Autonomous Passenger Ship (APS) is a characteristic instantiation of this development, aiming to transport people on urban waterways. Although emerging technologies deployed in such APS aim to facilitate the functions and operations of the navigation and communication systems, various safety and security risks are inherent to the communication infrastructure due to their interconnectivity. The aim of this work is to study the safety and cyber security of the communication system of an APS, namely the MilliAmpere2 APS. The six step model (SSM) is utilized to facilitate the joint analysis. The application of the SSM enables, among others, the capturing of relationships between cyber attacks and component failures, the assessment of safety and cyber security countermeasures, as well as, the synergies between them. It has been found that most countermeasures in both categories are reinforcing or are conditionally dependent on each other, while few antagonize each another. These findings will allow for improved design and implementation of integrated safety and security management solutions.

• Belalis, Ilias; Kavallieratos, Georgios; Gkioulos, Vasileios & Spathoulas, Georgios (2020). Enabling Defensive Deception by Leveraging Software Defined Networks. In Han, Lin (Eds.), INTERNET 2020 The Twelfth International Conference on Evolving Internet. International Academy, Research and Industry Association (IARIA). ISSN 9781612087962. p. 7–16. Full text in Research Archive Show summary

  Computer networks are critical for modern society and protecting their security is of high importance. Due to their increasing size and complexity providing the required cyber security counter measures has become a very difficult task. One of the most recent approaches is to employ defensive deception techniques, in order to provide to the attacker a false perception about the protected network and thus increase the effort that is needed to carry on a successful intrusion. In this paper we present a comprehensive literature review and a comparison of existing SDN based defensive deception methods. Additionally, we propose a novel deception mechanism that combines moving target and honeypots approaches and carry out extensive tests of its functionality.

• Kavallieratos, Georgios; Diamantopoulou, Vasiliki & Katsikas, Sokratis (2020). Shipping 4.0: Security requirements for the Cyber-Enabled Ship. IEEE Transactions on Industrial Informatics. ISSN 1551-3203. 16(10), p. 6617–6625. doi: 10.1109/TII.2020.2976840. Full text in Research Archive Show summary

  The cyber-enabled ship (C-ES) is either an autonomous or a remotely controlled vessel which relies on interconnected cyber physical-systems for its operations. Such systems are not well protected against cyberattacks. Considering the criticality of the functions that such systems provide, it is important to address their security challenges, thereby ensuring the ship's safe voyage. In this article, we leverage the maritime architectural framework reference architecture to analyze and describe the environment of the C-ES. We then apply the Secure Tropos methodology to systematically elicit the security requirements of the three most vulnerable cyber-physical systems (CPSs) onboard a C-ES, namely the automatic identification system (AIS), the electronic chart display information system, and the global maritime distress and safety system. The outcome is a set of cyber-security requirements for the C-ES ecosystem in general and these systems in particular.

• Kavallieratos, Georgios; Katsikas, Sokratis & Gkioulos, Vasileios (2019). Cyber-Attacks Against the Autonomous Ship, Computer Security ESORICS 2018 International Workshops, CyberICPS 2018 and SECPRE 2018, Barcelona, Spain, September 6–7, 2018, Revised Selected Papers. Springer. ISSN 9783030127862. p. 20–36. doi: 10.1007/978-3-030-12786-2_2. Full text in Research Archive Show summary

  Autonomous ships transferring valuable cargoes and humans in a more efficient and cost effective manner will soon be state of the art technology. Yet, their ICT system architecture and operations have not been defined in full detail. Moreover, multiple cyber security issues remain open and should be addressed. No study to date has analyzed fully the architecture of the autonomous ship, even less so have potential cyber threats and cyber attacks been identified. In this paper we identify and categorize systems that make up an autonomous ship, we propose a generic system architecture, and we analyze the cyber security of the ship by leveraging the STRIDE threat modeling methodology to identify potential cyber attacks, and to analyze the accordant risk. The results will support ship designers and industry towards improving the autonomous ship system architecture and making ship operations more secure.

• Kavallieratos, Georgios; Katsikas, Sokratis & Gkioulos, Vasileios (2019). Towards a Cyber-Physical Range. In Mathur, Aditya & Zhou, Jianying (Ed.), CPSS '19 Proceedings of the 5th on Cyber-Physical System Security Workshop. Association for Computing Machinery (ACM). ISSN 9781450367875. p. 25–34. doi: 10.1145/3327961.3329532. Full text in Research Archive
• Kavallieratos, Georgios; Chowdhury, Nabin; Katsikas, Sokratis; Gkioulos, Vasileios & Wolthusen, Stephen (2019). Threat Analysis for Smart Homes. Future Internet. 11(10). doi: 10.3390/fi11100207. Full text in Research Archive Show summary

  The development and deployment of highly dynamic, cyber+connected operational environments, such as smart homes, smart cities, and smart transportation systems, is increasing. The security analysis of such dynamic environments necessitates the use of dynamic risk assessment methodologies and the modeling of dynamically changing states. In this paper, we focus on the smart home environment, where the deployment of IoT devices increase the attack surface. We examine existing dynamic risk assessment methodologies, and by leveraging a smart home reference architecture we identify the security risks of a smart home’s physical and communication viewpoints, taking into consideration also dynamic operational aspects. Further, we develop a smart home network topology generator and a graph-based attack model to study dependencies among dynamically changing states and the propagation of a malware infection.

• Kavallieratos, Georgios; Gkioulos, Vasileios & Katsikas, Sokratis (2019). Threat Analysis in Dynamic Environments: The Case of the Smart Home. In Nikoletseas, Sotiris; Trigoni, Niki; Abdelzaher, Tarek & Picco, Gian Pietro (Ed.), Proceedings of the 15th Annual International Conference on Distributed Computing in Sensor Systems - DCOSS 2019. IEEE (Institute of Electrical and Electronics Engineers). ISSN 9781728105703. p. 234–240. doi: 10.1109/DCOSS.2019.00060. Full text in Research Archive Show summary

  The rapid advancement of information and communication technologies has fostered the development and deployment of complex interrelated systems, many of which also present highly dynamic operational characteristics. These are further integrated within highly connected environments such as smart cities, smart homes, and smart cars, continuously adopting new technological developments. In this article, we focus on the smart home environment, as a case study for such ecosystems, where the integration of IoT devices increases the attack surface, evaluating whether existing risk assessment methods can be utilized for the identification and monitoring of risks, while also capturing the dynamic operational aspects. Accordingly, we review existing dynamic risk assessment methodologies and we leverage a smart home reference architecture to identify the security threats of a smart home's physical and communication viewpoints by leveraging the STRIDE methodology and Microsoft's threat modelling tool.

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• Katsikas, Sokratis & Kavallieratos, Georgios (2022). Cybersecurity of the Unmanned Ship. In Maglaras, Leandros & Kantzavelou, Ioanna (Ed.), Cybersecurity Issues in Emerging Technologies. CRC Press. ISSN 9780367626174. Full text in Research Archive
• Katsikas, Sokratis & Kavallieratos, Georgios (2021). Cybersecurity of the unmanned ship. In Maglaras, Leandros & Kantzavelou, Ioanna (Ed.), Cybersecurity Issues in Emerging Technologies. CRC Press. ISSN 9780367626174. Full text in Research Archive

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