arXiv subjects

Evangelos K. Markakis

Publications and source records attributed to Evangelos K. Markakis.

8 recordsLinked to original sources

arXiv2026

QCMI-Based Quantum Markov Blanket Discovery for Semantic Quantum Networks

Quantum-enabled semantic communication networks (QESCs) leverage quantum technologies to transmit data meaning efficiently, yet face challenges from costly resources and noise. This letter introduces Quantum Markov Blankets (QMBs) to QESCs, a novel framework to isolate essential quantum information for semantic transmission. We prove QMBs' validity using quantum conditional mutual information, showing that they shield semantic content from irrelevant subsystems. An implementation strategy optimises QMB detection, reducing resource use. Simulations suggest that QMB-based QESCs cut qubit consumption by 50\%-75\% while enhancing fidelity compared with non-optimised quantum semantic schemes. Unlike classical approaches, QMBs offer inherent security by limiting an eavesdropper's access to classical data outside the blanket. We outline future directions, including real-time QMB adaptation. This work bridges quantum information theory and semantic communication, advancing resource-efficient and secure quantum networks.

quant-ph↗

arXiv2026

eBPF-Based Cybersecurity Mechanisms: A Systematic Literature Review

Extended Berkeley Packet Filter (eBPF) has emerged as a kernel-level framework enabling dynamic security enforcement in modern operating systems. While eBPF's cybersecurity potential has attracted significant attention, existing work remains fragmented across domains, evaluation methodologies, and deployment contexts. This systematic literature review applies PRISMA methodology to identify, categorize, and synthesize peer-reviewed research on eBPF-based cybersecurity mechanisms. Following a structured screening of 3,735 records from six databases, 54 primary studies (2018-2026) were analyzed and organized into a seven-domain taxonomy: DDoS mitigation, intrusion detection, IoT security, container security, microservice protection, networking, and security tools. Analysis reveals eBPF enables low-overhead security enforcement (median 2.4% CPU overhead [1.1-8.6%], ranging from nanosecond-scale costs for infrequent hooks to 10-20% for kernel hot paths) with high detection accuracy (94-99%). It particularly excels in kernel-level monitoring, real-time packet processing, and cloud-native workload protection. However, significant challenges persist: verifier-imposed constraints limit algorithm complexity, 85.1% (46/54) of studies require low-level programming expertise, kernel version fragmentation hinders portability, and 96.2% (52/54) of research fails to address eBPF's own vulnerabilities. This review identifies critical research gaps in multi-tenant isolation, adversarial machine learning (ML) robustness, production validation, and standardized evaluation frameworks. By consolidating fragmented knowledge and highlighting architectural trade-offs between safety and expressiveness, this work provides a foundation for next-generation eBPF security systems and actionable directions for kernel programmability research.

cs.CR↗

arXiv2026

Foundation Models in Robotics: A Comprehensive Review of Methods, Models, Datasets, Challenges and Future Research Directions

Over the recent years, the field of robotics has been undergoing a transformative paradigm shift from fixed, single-task, domain-specific solutions towards adaptive, multi-function, generalpurpose agents, capable of operating in complex, open-world, and dynamic environments. This tremendous advancement is primarily driven by the emergence of Foundation Models (FMs), i.e., large-scale neural-network architectures trained on massive, heterogeneous datasets that provide unprecedented capabilities in multi-modal understanding and reasoning, long-horizon planning, and cross-embodiment generalization. In this context, the current study provides a holistic, systematic, and in-depth review of the research landscape of FMs in robotics. In particular, the evolution of the field is initially delineated through five distinct research phases, spanning from the early incorporation of Natural Language Processing (NLP) and Computer Vision (CV) models to the current frontier of multi-sensory generalization and real-world deployment. Subsequently, a highly-granular taxonomic investigation of the literature is performed, examining the following key aspects: a) the employed FM types, including LLMs, VFMs, VLMs, and VLAs, b) the underlying neural-network architectures, c) the adopted learning paradigms, d) the different learning stages of knowledge incorporation, e) the major robotic tasks, and f) the main real-world application domains. For each aspect, comparative analysis and critical insights are provided. Moreover, a report on the publicly available datasets used for model training and evaluation across the considered robotic tasks is included. Furthermore, a hierarchical discussion on the current open challenges and promising future research directions in the field is incorporated.

cs.RO↗

arXiv2026

The Decentralisation Paradox in Digital Identity: Centralising Decentralisation with Digital Wallets?

Digital identity is shifting from service- and network-centric approaches toward user-centric ones that promise users increased control over their data. Despite their decentralised design, such approaches often reintroduce centralised components in different forms. This paper conceptualises this tension as the decentralisation paradox and shows that user-centric architectures tend to redistribute rather than eliminate centralisation. Drawing on Critical Systems Thinking (CST), digital identity is framed as a "wicked problem" that spans the technical, legal, social and ethical dimensions. It introduces the Digital Identity Tetrahedron as a multidimensional framework for analysing decentralisation in digital identity ecosystems. Understanding these interdependencies is essential for designing reliable architectures and ensuring that the next generation of digital identity surpasses superficial decentralisation.

cs.CR↗

arXiv2026

Human Vulnerability Assessment in Cybersecurity: A Systematic Literature Review of Methods, Models, and Instruments

In cybersecurity, vulnerability assessment has typically focused on identifying and measuring vulnerabilities within digital assets and technical infrastructures. However, there is growing recognition that this approach alone is inadequate without a structured examination of the human factor, which is becoming more frequently targeted and manipulated by cyber adversaries. Human vulnerabilities extend beyond individual susceptibility to cyber threats, encompassing a wide array of psychological, cognitive, behavioral, social, and contextual factors that can, whether unintentionally or intentionally, jeopardize the security and integrity of systems and data. Despite this recognition, human vulnerability assessment remains fragmented, often addressed from a static rather than a dynamic perspective, and with limited focus on the ways it propagates across individuals and systems; a growing body of literature has explored specific facets of the issue, including one-time assessments of security behavior, user awareness, and, to a degree, intentional insider threats and their detection. This research offers a systematic literature review (SLR) of Human Vulnerability Assessment (HVA) in cybersecurity, including methods, models, and instruments proposed for the conceptual or practical assessment of human vulnerabilities across various dimensions. Following the PRISMA framework, this review gathers relevant studies published from 2017 to 2025, aiming to investigate whether any assessment methods, models, or instruments exist that address the entire spectrum of human vulnerabilities dynamically. The findings highlight gaps and limitations in current proposed solutions and identify areas for further investigation regarding holistic assessment that simultaneously and dynamically considers the entire spectrum of both the unintentional and intentional dimensions of human vulnerability.

cs.CR↗

arXiv2026

Kernel-Based ReLU Approximation for Homomorphic Encryption-Compatible Privacy-preserving Deep Learning Models

As privacy concerns in AI technologies continue to grow, Homomorphic Encryption (HE) offers a way to perform computations on encrypted data without the need of decryption during operations. However, HE is limited to addition and multiplication, making non-linear functions incompatible in their original form. This limitation has become more critical with the widespread use of Large Language Models (LLMs), where the non-linearity of activation functions such as the Rectified Linear Unit (ReLU) poses challenges for deployment in privacy-preserving Natural Language Processing (NLP) settings. This paper proposes a kernel-based approximation of ReLU, enabling its use within HE-constrained settings and thus contributing a critical step toward supporting privacy-preserving LLMs. A smooth kernel-based function, mimicking ReLU, is approximated using a second-degree polynomial, inspired by Jackson's theorem, to achieve low multiplicative depth. The proposed method is trained and assessed directly on token embeddings from pre-trained LLMs and evaluated in various scenarios, from simulated and tokenized data to deep learning and transformer models. Results show improved approximation fidelity, supporting the method's suitability for secure and privacy-preserving inference in various tasks.

cs.CR↗

arXiv2025

Accurate and lightweight dehazing via multi-receptive-field non-local network and novel contrastive regularization

Recently, deep learning-based methods have dominated image dehazing domain. A multi-receptive-field non-local network (MRFNLN) consisting of the multi-stream feature attention block (MSFAB) and the cross non-local block (CNLB) is presented in this paper to further enhance the performance. We start with extracting richer features for dehazing. Specifically, a multi-stream feature extraction (MSFE) sub-block, which contains three parallel convolutions with different receptive fields (i.e., $1\times 1$, $3\times 3$, $5\times 5$), is designed for extracting multi-scale features. Following MSFE, an attention sub-block is employed to make the model adaptively focus on important channels/regions. These two sub-blocks constitute our MSFAB. Then, we design a cross non-local block (CNLB), which can capture long-range dependencies beyond the query. Instead of the same input source of query branch, the key and value branches are enhanced by fusing more preceding features. CNLB is computation-friendly by leveraging a spatial pyramid down-sampling (SPDS) strategy to reduce the computation and memory consumption without sacrificing the performance. Last but not least, a novel detail-focused contrastive regularization (DFCR) is presented by emphasizing the low-level details and ignoring the high-level semantic information in a representation space specially designed for dehazing. Comprehensive experimental results demonstrate that the proposed MRFNLN model outperforms recent state-of-the-art dehazing methods with less than 1.5 Million parameters.

cs.CV↗

arXiv2021

A Survey on Human and Personality Vulnerability Assessment in Cyber-security: Challenges, Approaches, and Open Issues

These days, cyber-criminals target humans rather than machines since they try to accomplish their malicious intentions by exploiting the weaknesses of end users. Thus, human vulnerabilities pose a serious threat to the security and integrity of computer systems and data. The human tendency to trust and help others, as well as personal, social, and cultural characteristics, are indicative of the level of susceptibility that one may exhibit towards certain attack types and deception strategies. This work aims to investigate the factors that affect human susceptibility by studying the existing literature related to this subject. The objective is also to explore and describe state of the art human vulnerability assessment models, current prevention, and mitigation approaches regarding user susceptibility, as well as educational and awareness raising training strategies. Following the review of the literature, several conclusions are reached. Among them, Human Vulnerability Assessment has been included in various frameworks aiming to assess the cyber security capacity of organizations, but it concerns a one time assessment rather than a continuous practice. Moreover, human maliciousness is still neglected from current Human Vulnerability Assessment frameworks; thus, insider threat actors evade identification, which may lead to an increased cyber security risk. Finally, this work proposes a user susceptibility profile according to the factors stemming from our research.

cs.CR↗