Christos Chrysoulas

Dr. Christos Chrysoulas

Edinburgh Napier University
orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
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Pavlos PapadopoulosPavlos Papadopoulos
Pavlos Papadopoulos
OEOliver Thornewill von Essen
Oliver Thornewill von Essen
Nikolaos PitropakisNikolaos Pitropakis
Nikolaos Pitropakis
Christos ChrysoulasChristos Chrysoulas
Christos Chrysoulas
Alexios MylonasAlexios Mylonas
Alexios Mylonas
William Johnston BuchananWilliam Johnston Buchanan
William Johnston Buchanan
As the internet continues to be populated with new devices and emerging technologies, the attack surface grows exponentially. Technology is shifting towards a profit-driven Internet of Things market where security is an afterthought. Traditional defending approaches are no longer sufficient to detect both known and unknown attacks to high accuracy. Machine learning intrusion detection systems have proven their success in identifying unknown attacks with high precision. Nevertheless, machine learning models are also vulnerable to attacks. Adversarial examples can be used to evaluate the robustness of a designed model before it is deployed. Further, using adversarial examples is critical to creating a robust model designed for an adversarial environment. Our work evaluates both traditional machine learning and deep learning models’ robustness using the Bot-IoT dataset. Our methodology included two main approaches. First, label poisoning, used to cause incorrect classification by the model. Second, the fast gradient sign method, used to evade detection measures. The experiments demonstrated that an attacker could manipulate or circumvent detection with significant probability.

7 March 2025 in Sensors
Verified
Journal Article
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YYYagmur Yigit
Yagmur Yigit
Mohamed Amine FerragMohamed Amine Ferrag
Mohamed Amine Ferrag
Mohamed Chahine GhanemMohamed Chahine Ghanem
Mohamed Chahine Ghanem
Iqbal H. SarkerIqbal H. Sarker
Iqbal H. Sarker
Leandros MaglarasLeandros Maglaras
Leandros Maglaras
HJHelge Janicke
Helge Janicke
Critical National Infrastructures (CNIs)—including energy grids, water systems, transportation networks, and communication frameworks—are essential to modern society yet face escalating cybersecurity threats. This review paper comprehensively analyzes AI-driven approaches for Critical Infrastructure Protection (CIP). We begin by examining the reliability of CNIs and introduce established benchmarks for evaluating Large Language Models (LLMs) within cybersecurity contexts. Next, we explore core cybersecurity issues, focusing on trust, privacy, resilience, and securability in these vital systems. Building on this foundation, we assess the role of Generative AI and LLMs in enhancing CIP and present insights on applying Agentic AI for proactive defense mechanisms. Finally, we outline future directions to guide the integration of advanced AI methodologies into protecting critical infrastructures. Our paper provides a strategic roadmap for researchers and practitioners committed to fortifying national infrastructures against emerging cyber threats through this synthesis of current challenges, benchmarking strategies, and innovative AI applications.

3 February 2023 in Computers
Verified
Journal Article
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CKChathuranga Sampath Kalutharage
Chathuranga Sampath Kalutharage
Xiaodong LiuXiaodong Liu
Xiaodong Liu
Christos ChrysoulasChristos Chrysoulas
Christos Chrysoulas
Nikolaos PitropakisNikolaos Pitropakis
Nikolaos Pitropakis
Pavlos PapadopoulosPavlos Papadopoulos
Pavlos Papadopoulos
The modern digitized world is mainly dependent on online services. The availability of online systems continues to be seriously challenged by distributed denial of service (DDoS) attacks. The challenge in mitigating attacks is not limited to identifying DDoS attacks when they happen, but also identifying the streams of attacks. However, existing attack detection methods cannot accurately and efficiently detect DDoS attacks. To this end, we propose an explainable artificial intelligence (XAI)-based novel method to identify DDoS attacks. This method detects abnormal behaviours of network traffic flows by analysing the traffic at the network layer. Moreover, it chooses the most influential features for each anomalous instance with influence weight and then sets a threshold value for each feature. Hence, this DDoS attack detection method defines security policies based on each feature threshold value for application-layer-based, volumetric-based, and transport control protocol (TCP) state-exhaustion-based features. Since the proposed method is based on layer three traffic, it can identify DDoS attacks on both Internet of Things (IoT) and traditional networks. Extensive experiments were performed on the University of Sannio, Benevento Instrution Detection System (USB-IDS) dataset, which consists of different types of DDoS attacks to test the performance of the proposed solution. The results of the comparison show that the proposed method provides greater detection accuracy and attack certainty than the state-of-the-art methods.

1 October 2014
Verified
Conference Paper
Closed access
FBFredrik Blomstedt
Fredrik Blomstedt
LFLuis Miguel Moreira Lino Ferreira
Luis Miguel Moreira Lino Ferreira
MKMarkus Klisics
Markus Klisics
Christos ChrysoulasChristos Chrysoulas
Christos Chrysoulas
ISIker Martinez de Soria
Iker Martinez de Soria
Pal VargaPal Varga
Pal Varga
The Arrowhead project aims to address the technical and applicative issues associated with cooperative automation based on Service Oriented Architectures. The problems of developing such kind of systems are mainly due to the lack of adequate development and service documentation methodologies, which would ease the burden of reusing services on different applications. The Arrowhead project proposes a technical framework to efficiently support the development of such systems, which includes several tools for documentation of services and to support the development of SOA-based installations. The work presented in this paper describes the approach which has been developed for the first generation pilots to support the documentation of their structural services. Each service, system and system-of-systems within the Arrowhead Framework must be documented and described in such way that it can be implemented, tested and deployed in an interoperable way. This paper presents the first steps of realizing the Arrowhead vision for interoperable services, systems and systems-of-systems.

25 September 2020 in Sensors
Verified
Journal Article
Open access
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Brahim El BoudaniBrahim El Boudani
Brahim El Boudani
LKLoizos Kanaris
Loizos Kanaris
AKAkis Kokkinis
Akis Kokkinis
MKMichalis Kyriacou
Michalis Kyriacou
Christos ChrysoulasChristos Chrysoulas
Christos Chrysoulas
Tasos DagiuklasTasos Dagiuklas
Tasos Dagiuklas
In the near future, the fifth-generation wireless technology is expected to be rolled out, offering low latency, high bandwidth and multiple antennas deployed in a single access point. This ecosystem will help further enhance various location-based scenarios such as assets tracking in smart factories, precise smart management of hydroponic indoor vertical farms and indoor way-finding in smart hospitals. Such a system will also integrate existing technologies like the Internet of Things (IoT), WiFi and other network infrastructures. In this respect, 5G precise indoor localization using heterogeneous IoT technologies (Zigbee, Raspberry Pi, Arduino, BLE, etc.) is a challenging research area. In this work, an experimental 5G testbed has been designed integrating C-RAN and IoT networks. This testbed is used to improve both vertical and horizontal localization (3D Localization) in a 5G IoT environment. To achieve this, we propose the DEep Learning-based co-operaTive Architecture (DELTA) machine learning model implemented on a 3D multi-layered fingerprint radiomap. The DELTA begins by estimating the 2D location. Then, the output is recursively used to predict the 3D location of a mobile station. This approach is going to benefit use cases such as 3D indoor navigation in multi-floor smart factories or in large complex buildings. Finally, we have observed that the proposed model has outperformed traditional algorithms such as Support Vector Machine (SVM) and K-Nearest Neighbor (KNN).