TY - CHAP AU - Wilson, Valdez AU - Baniata, Hamza AU - Márkus, András AU - Kertész, Attila ED - Zeinalipour, Demetris ED - Blanco Heras, Dora ED - Pallis, George ED - Herodotou, Herodotos ED - Trihinas, Demetris ED - Balouek, Daniel ED - Diehl, Patrick ED - Cojean, Terry ED - Fürlinger, Karl ED - Kirkeby, Maja Hanne ED - Nardellli, Matteo ED - Di Sanzo, Pierangelo TI - Towards a Simulation as a Service Platform for the Cloud-to-Things Continuum T2 - Euro-Par 2023: Parallel Processing Workshops PB - Springer Nature Switzerland CY - Cham SN - 9783031488030 T3 - Lecture Notes in Computer Science, ISSN 0302-9743 ; 14352. PY - 2024 SP - 65 EP - 75 PG - 11 DO - 10.1007/978-3-031-48803-0_6 UR - https://m2.mtmt.hu/api/publication/34795664 ID - 34795664 LA - English DB - MTMT ER - TY - JOUR AU - Baniata, Hamza AU - Anaqreh, Ahmad AU - Kertész, Attila TI - Distributed scalability tuning for evolutionary sharding optimization with Random-equivalent security in permissionless Blockchain JF - INTERNET OF THINGS J2 - INTERNET THINGS-NETH VL - 24 PY - 2023 PG - 17 SN - 2543-1536 DO - 10.1016/j.iot.2023.100955 UR - https://m2.mtmt.hu/api/publication/34167552 ID - 34167552 LA - English DB - MTMT ER - TY - THES AU - Baniata, Hamza TI - Integrating Blockchain and Fog Computing Technologies for Efficient Privacy-preserving Systems PB - Szegedi Tudományegyetem PY - 2023 SP - 175 DO - 10.14232/phd.11555 UR - https://m2.mtmt.hu/api/publication/34132495 ID - 34132495 AB - This PhD dissertation concludes a three-year long research journey on the integration of Fog Computing and Blockchain technologies. The main aim of such integration is to address the challenges of each of these technologies, by integrating it with the other. Blockchain technology (BC) is a distributed ledger technology in the form of a distributed transactional database, secured by cryptography, and governed by a consensus mechanism. It was initially proposed for decentralized cryptocurrency applications with practically proven high robustness. Fog Computing (FC) is a geographically distributed computing architecture, in which various heterogeneous devices at the edge of network are ubiquitously connected to collaboratively provide elastic computation services. FC provides enhanced services closer to end-users in terms of time, energy, and network load. The integration of FC with BC can result in more efficient services, in terms of latency and privacy, mostly required by Internet of Things systems. LA - English DB - MTMT ER - TY - JOUR AU - Baniata, Hamza AU - Kertész, Attila TI - Approaches to Overpower Proof-of-Work Blockchains Despite Minority JF - IEEE ACCESS J2 - IEEE ACCESS VL - 11 PY - 2023 SP - 2952 EP - 2967 PG - 16 SN - 2169-3536 DO - 10.1109/ACCESS.2023.3234322 UR - https://m2.mtmt.hu/api/publication/33692160 ID - 33692160 AB - Blockchain (BC) technology has been established in 2009 by Nakamoto, using the Proof-of-Work (PoW) to reach consensus in public permissionless networks (Praveen et al., 2020). Since then, several consensus algorithms were proposed to provide equal (or higher) levels of security, democracy, and scalability, yet with lower levels of energy consumption. However, Nakamoto's model (a.k.a. Bitcoin) still dominates as the most trusted model in the described sittings since alternative solutions might provide lower energy consumption and higher scalability, but they would always require deviating the system towards unrecommended centralization or lower levels of security. That is, Nakamoto's model claims to tolerate (up to) < 50% of the network being controlled by a dishonest party (minority), which cannot be realized in alternative solutions without sacrificing the full decentralization property. In this paper, we investigate this tolerance claim, and we review several approaches that can be used to undermine/overpower PoW-based BCs, even with minority. We discuss those BCs taking Bitcoin as a representative application, where needed. However, the presented approaches can be applied in any PoW-based BC. Specifically, we technically discuss how a dishonest miner in minority, can take over the network using improved Brute-forcing, AI-assisted mining, Quantum Computing, Sharding, Partial Pre-imaging, Selfish mining, among other approaches. Our review serves as a needed collective technical reference (concluding more than 100 references), for practitioners and researchers, who either seek a reliable security implementation of PoW-based BC applications, or seek a comparison of PoW-based, against other BCs, in terms of adversary tolerance. LA - English DB - MTMT ER - TY - JOUR AU - Pflanzner, Tamás AU - Baniata, Hamza AU - Kertész, Attila TI - Latency Analysis of Blockchain-Based SSI Applications JF - FUTURE INTERNET J2 - FUTURE INTERNET VL - 14 PY - 2022 IS - 10 PG - 13 SN - 1999-5903 DO - 10.3390/fi14100282 UR - https://m2.mtmt.hu/api/publication/33151104 ID - 33151104 N1 - Export Date: 23 March 2023 Correspondence Address: Kertesz, A.; Software Engineering Department, Hungary; email: keratt@inf.u-szeged.hu AB - Several revolutionary applications have been built on the distributed ledgers of blockchain (BC) technology. Besides cryptocurrencies, we can find many other application fields in smart systems exploiting smart contracts and Self Sovereign Identity (SSI) management. The Hyperledger Indy platform is a suitable open-source solution for realizing permissioned BC systems for SSI projects. SSI applications usually require short response times from the underlying BC network, which may vary highly depending on the application type, the used BC software, and the actual BC deployment parameters. To support the developers and users of SSI applications, we present a detailed latency analysis of a private permissioned BC system built with Indy and Aries. To streamline our experiments, we developed a Python application using containerized Indy and Aries components from official Hyperledger repositories. We deployed our experimental application on multiple virtual machines in the public Google Cloud Platform and on our local, private cloud using a Docker platform with Kubernetes. We evaluated and compared their performance with the metrics of reading and writing response latency. We found that the local Indy ledger reads 30–50% faster, and writes 65–85% faster than the Indy ledger running on the Google Cloud Platform. LA - English DB - MTMT ER - TY - JOUR AU - Kertész, Attila AU - Baniata, Hamza TI - Consistency Analysis of Distributed Ledgers in Fog-Enhanced Blockchains JF - LECTURE NOTES IN COMPUTER SCIENCE J2 - LNCS VL - 13098 PY - 2022 SP - 393 EP - 404 PG - 12 SN - 0302-9743 DO - 10.1007/978-3-031-06156-1_31 UR - https://m2.mtmt.hu/api/publication/32930145 ID - 32930145 N1 - Conference code: 279039 Export Date: 12 July 2022 Correspondence Address: Kertesz, A.; University of Szeged, Dugonics ter 13, Hungary; email: keratt@inf.u-szeged.hu Funding details: Hungarian Scientific Research Fund, OTKA, OTKA FK 131793, TKP2021-NVA-09 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding text 1: This research was supported by the Hungarian Scientific Research Fund under the grant number OTKA FK 131793, and by the national project TKP2021-NVA-09 implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NVA funding scheme. AB - Both revolutionary technologies of Fog Computing (FC) and Blockchain (BC) serve as enablers for enhanced, people-centric trusted applications, and they do meet in the provision of higher standards and expectations. In this paper, we address the reliability of fog-enhanced BC systems by analyzing the forking phenomenon under different conditions, and provide a reliable Distributed Ledger (DL) consistency assessment. We use the FoBSim tool that is specifically designed to mimic and emulate realistic FC-BC integration, in which we deploy the Proof-of-Work (PoW) consensus algorithm and analyze the forking probability under fluctuating conditions. Based on our results, we propose an inconsistency formula, which can quantitatively describe how consistent the DL in a BC system can be. Finally, we show how to deploy this formula in a decision making model for indicating optimal deployment features of a BC network in a Fog-enhanced system. © 2022, Springer Nature Switzerland AG. LA - English DB - MTMT ER - TY - JOUR AU - Baniata, Hamza AU - Kertész, Attila TI - PriFoB: A Privacy-aware Fog-enhanced Blockchain-based system for Global Accreditation and Credential Verification JF - JOURNAL OF NETWORK AND COMPUTER APPLICATIONS J2 - J NETW COMPUT APPL VL - 205 PY - 2022 PG - 20 SN - 1084-8045 DO - 10.1016/j.jnca.2022.103440 UR - https://m2.mtmt.hu/api/publication/32930119 ID - 32930119 N1 - Export Date: 12 July 2022 Correspondence Address: Baniata, H.; Department of Software Engineering, Hungary; email: baniatah@inf.u-szeged.hu Funding details: 5750 Funding details: Horizon 2020 Framework Programme, H2020 Funding details: Hungarian Scientific Research Fund, OTKA, FK 131793 Funding details: Horizon 2020, 957228, TKP2021-NVA-09 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding text 1: The research leading to these results has received funding from the TruBlo project of the European Union's Horizon 2020 research and innovation program under grant agreement No. 957228, and from the national project TKP2021-NVA-09 implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, and from the University of Szeged Open Access Fund under the grant number 5750. All authors have read and agreed to the published version of the manuscript. Funding text 2: The research leading to these results has received funding from the TruBlo project of the European Union’s Horizon 2020 research and innovation program under grant agreement No. 957228 , and from the national project TKP2021-NVA-09 implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund , and from the University of Szeged Open Access Fund under the grant number 5750 . All authors have read and agreed to the published version of the manuscript. Funding text 3: Attila Kertesz is currently with the University of Szeged, Szeged, Hungary. He is an associate professor at the Department of Software Engineering, leading the IoT-Cloud research group. He graduated as a program-designer mathematician in 2005, received his Ph.D. degree at the SZTE Doctoral School of Computer Science in 2011, and habilitated at the University of Szeged in 2017. His research interests include the federative management of Blockchain, IoT, Fog and Cloud systems, and interoperability issues of distributed systems in general. He is the leader of the FogBlock4Trust sub-grant project of the TruBlo EU H2020 project, and the OTKA FK 131793 national project financed by the Hungarian Scientific Research Fund. He is also a Management Committee member of the CERCIRAS and INDAIRPOLLNET EU Cost Actions. He has more than 130 publications with more than 1100 citations. AB - Trusted online credential management solutions are needed for instant and practical verification. Most of the available frameworks targeting this field violate the privacy of end-users or lack sufficient solutions in terms of security and Quality-of-Service (QoS). In this paper, we propose a Privacy-aware Fog-enhanced Blockchain-based online credential management solution, namely PriFoB. Our proposed solution adopts a public permissioned Blockchain model with different reliable encryption schemes, standardized Zero-Knowledge-Proofs (ZKPs) and Digital Signatures (DSs) within a Fog–Blockchain integrated framework, which is also GDPR compliant. We deploy both the Proof-of-Authority (PoA) and the Signatures-of-Work (SoW) consensus algorithms for efficient and secure handling of Verifiable Credentials (VCs) and global accreditation of VC issuers, respectively. Furthermore, we propose a novel three-dimensional DAG-based model of the Distributed Ledger (3DDL), and provide a ready-to-deploy PriFoB implementation. We discuss insights regarding the utilization and the potential of PriFoB, and evaluate it in terms of security, privacy, latency, throughput and power utilization. We analyze its performance in different layers of a Fog-enabled cloud architecture with simulation and emulation, and we show that PriFoB outperforms several Blockchain-based solutions utilizing Ethereum, Hyperledger Fabric, Hyperledger Besu and Hyperledger Indy platforms. © 2022 The Author(s) LA - English DB - MTMT ER - TY - CHAP AU - Baniata, Hamza AU - Pflanzner, Tamás AU - Feher, Zoltan AU - Kertész, Attila ED - Maarten, van Steen ED - Donald, Ferguson ED - Claus, Pahl TI - Latency Assessment of Blockchain-based SSI Applications Utilizing Hyperledger Indy T2 - Proceedings of the 12th International Conference on Cloud Computing and Services Science PB - SciTePress CY - Setubal SN - 9789897585708 PY - 2022 SP - 264 EP - 271 PG - 8 DO - 10.5220/0011082300003200 UR - https://m2.mtmt.hu/api/publication/32808786 ID - 32808786 N1 - Conference code: 183560 Cited By :2 Export Date: 6 April 2023 Funding details: Nemzeti Kutatási, Fejlesztési és Innovaciós Alap, NKFIA Funding details: Innovációs és Technológiai Minisztérium Funding text 1: The research leading to these results has received funding from the national project TKP2021-NVA-09 implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, and from the UNKP-21-4 New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation Fund. The experiments presented in this paper are based upon work supported by Google Cloud. LA - English DB - MTMT ER - TY - JOUR AU - Baniata, Hamza AU - Anaqreh, Ahmad AU - Kertész, Attila TI - DONS: Dynamic Optimized Neighbor Selection for smart blockchain networks JF - FUTURE GENERATION COMPUTER SYSTEMS J2 - FUTUR GENER COMP SYST VL - 130 PY - 2022 SP - 75 EP - 90 PG - 16 SN - 0167-739X DO - 10.1016/j.future.2021.12.010 UR - https://m2.mtmt.hu/api/publication/32588616 ID - 32588616 N1 - Department of Software Engineering, University of Szeged, Szeged, 6720, Hungary Department of Computational Optimization, University of Szeged, Szeged, 6720, Hungary Export Date: 12 January 2022 CODEN: FGCSE Correspondence Address: Baniata, H.; Department of Software Engineering, Hungary; email: baniatah@inf.u-szeged.hu Funding details: 5544 Funding details: Horizon 2020 Framework Programme, H2020, 957228 Funding details: Hungarian Scientific Research Fund, OTKA, FK 131793, OTKA FK 131793 Funding details: Horizon 2020 Funding details: European Regional Development Fund, ERDF Funding details: Magyarország Kormánya Funding details: National Research, Development and Innovation Office Funding text 1: This research work was supported by the Hungarian Scientific Research Fund , under the grant number OTKA FK 131793 , and by the TruBlo project of the European Union’s Horizon 2020 research and innovation program under grant agreement No. 957228 , and by the National Research, Development and Innovation Office within the framework of the Artificial Intelligence National Laboratory Programme, and by the University of Szeged Open Access Fund under the grant number 5544 . Funding text 2: This research work was supported by the Hungarian Scientific Research Fund under the grant number OTKA FK 131793 , and by the TruBlo project of the European Union’s Horizon 2020 research and innovation program under grant agreement No. 957228 , and by the National Research, Development and Innovation Office within the framework of the Artificial Intelligence National Laboratory Programme, and by the University of Szeged Open Access Fund under the grant number 5544 . Funding text 3: Attila Kertesz is currently with the University of Szeged, Szeged, Hungary. He is an associate professor at the Department of Software Engineering, leading the IoT-Cloud research group. He graduated as a program-designer mathematician in 2005, received his Ph.D. degree at the SZTE Doctoral School of Computer Science in 2011, and habilitated at the University of Szeged in 2017. His research interests include the federative management of Blockchain, IoT, Fog and Cloud systems, and interoperability issues of distributed systems in general. He is the leader of the FogBlock4Trust sub-grant project of the TruBlo EU H2020 project, and the OTKA FK 131793 national project financed by the Hungarian Scientific Research Fund, and a work package leader in the GINOPIoLT project, financed by the Hungarian Government and the European Regional Development Fund. He is also a Management Committee member of the CERCIRAS and INDAIRPOLLNET Cost Actions. He has more than 100 publications with more than 1000 citations. Funding text 4: This research work was supported by the Hungarian Scientific Research Fund, under the grant number OTKA FK 131793, and by the TruBlo project of the European Union's Horizon 2020 research and innovation program under grant agreement No. 957228, and by the National Research, Development and Innovation Office within the framework of the Artificial Intelligence National Laboratory Programme, and by the University of Szeged Open Access Fund under the grant number 5544.This research work was supported by the Hungarian Scientific Research Fund under the grant number OTKA FK 131793, and by the TruBlo project of the European Union's Horizon 2020 research and innovation program under grant agreement No. 957228, and by the National Research, Development and Innovation Office within the framework of the Artificial Intelligence National Laboratory Programme, and by the University of Szeged Open Access Fund under the grant number 5544. AB - Blockchain (BC) systems mainly depend on the consistent state of the Distributed Ledger (DL) at different logical and physical places of the network. The majority of network nodes need to be enforced to use one or both of the following approaches to remain consistent: (i) to wait for certain delays (i.e. by requesting a hard puzzle solution as in PoW and PoUW, or to wait for random delays as in PoET, etc.) (ii) to propagate shared data through shortest possible paths within the network. The first approach may cause higher energy consumption and/or lower throughput rates if not optimized, and in many cases these features are conventionally fixed. Therefore, it is preferred to enhance the second approach with some optimization. Previous works for this approach have the following drawbacks: they may violate the identity privacy of miners, only locally optimize the Neighbor Selection method (NS), do not consider the dynamicity of the network, or require the nodes to know the precise size of the network at all times. In this paper, we address these issues by proposing a Dynamic and Optimized NS protocol called DONS, using a novel privacy-aware leader election within the public BC called AnoLE, where the leader anonymously solves the The Minimum Spanning Tree problem (MST) of the network in polynomial time. Consequently, miners are informed about the optimum NS according to the current state of network topology. We analytically evaluate the complexity, the security and the privacy of the proposed protocols against state-of-the-art MST solutions for DLs and well known attacks. Additionally, we experimentally show that the proposed protocols outperform state-of-the-art NS solutions for public BCs. Our evaluation shows that the proposed DONS and AnoLE protocols are secure, private, and they acutely outperform all current NS solutions in terms of block finality and fidelity. © 2021 The Author(s) LA - English DB - MTMT ER - TY - CONF AU - Baniata, Hamza AU - Dragi, Kimovski AU - Radu, Prodan AU - Kertész, Attila ED - Padma, Iyenghar ED - Gordana, Rakic TI - Towards Blockchain-based Smart Systems T2 - Proceedings of the First Workshop on Connecting Education and Research Communities for an Innovative Resource Aware Society (CERCIRAS) T3 - CEUR Workshop Proceedings, ISSN 1613-0073 ; 3145. PY - 2021 PG - 10 UR - https://m2.mtmt.hu/api/publication/32855236 ID - 32855236 AB - The unprecedented pace of technological development in smart systems, incorporating sensing, actuation, and control functions, have the following properties and needs: (.) they are interconnected and need scalable, virtualized resources to run, store and process data, (⋯.) they are mobile and can potentially access and build on user data made available by smartphones and tablets, and (⋯⋯) they are getting smarter, so they may get access to user data provided by connected smart devices. As the number of smart devices in smart systems grows, the vast amount of data they produce requires high-performance computational and storage services for processing and analysis and other novel techniques and methods that enhance these services and their management. Blockchain applications have been proposed in a wide variety of environments such as distributed voting, eHealth, Mobile Computing, Internet of Vehicles, etc. We believe that integrating Blockchain technology with smart applications for managing data of mobile devices can further enhance the privacy and security requirements of current complex systems. In this paper, we discuss Blockchain-integration possibilities for smart systems to support the efficient, secure, and privacy-aware execution of smart applications. We propose a design space where issues need to be solved in different layers of such integrated systems. Accordingly, we envision a Blockchain-enabled simulation framework capable of analysing the integration possibilities with fog/edge and cloud infrastructures at different layers of smart systems. The framework will be able to model and analyse the behavior of Blockchain networks in large-scale fog-enhanced smart systems while using different AI methods. LA - English DB - MTMT ER -