EDBT 2026 Demo / reviewers in the wild / expert
Grigorios Chrysos 0001
dblp:75/6117-1 · also Gregory Chrysos
· DBLP profile ↗
22ranked-venue papers
6as first author
3since 2021 · last 2025
—ORCID · none
Domains — the database's venue-derived domains; a paper can count in several
Systems, architecture and hardware · 21 · 5 first-author · 3 since 2021Software engineering, systems software and programming languages · 3 · 1 since 2021Applied, interdisciplinary, general and emerging computing · 1 · 1 first-author
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2025 | Multi-Partner Project: CyberSecDome - Framework for Secure, Collaborative, and Privacy-Aware Incident Handling for Digital InfrastructureabstractDigital infrastructure is vital for the economy, democracy, and everyday life, yet it is becoming increasingly vulnerable to strategic cyber-attacks. These attacks can lead to significant disruptions, resulting in widespread service outages, financial losses, and a decline in public trust. Ensuring resilience is difficult due to the infrastructure's complexity, the large volume of data involved, and the growing need for quick, coordinated responses. In the EU Horizon project CyberSecDome, we propose a multi-layered framework that provides AI-driven solutions for incident prediction and detection, automated testing, risk assessment, and rapid incident response, supporting continuity amid complex, large-scale cyber threats. Additionally, Cyber-SecDome introduces a virtual reality interface to enhance AI model explainability and provide real-time contextual awareness of ongoing attacks and defense mechanisms. It also enables privacy-aware model sharing across AI systems, fostering secure collaboration among different domes. Mohammad Hamad, Michael Kühr, Haralambos Mouratidis, Eleni-Maria Kalogeraki, Christos-Antonios Gizelis, Dimitrios Papanikas, Athanasios Bountioukos-Spinaris, Charilaos Skandylas, Evangelos Raptis, Andreas Alexopoulos, Grigorios Chrysos 0001, Mina Marmpena, Sevasti Politi, Konstantinos Lieros, Nikolaos Papagiannopoulos, Iordanis Xanthopoulos, Spyridon Papastergiou, Sotiris Ioannidis, Mikael Asplund, Marc-Oliver Pahl, Sebastian Steinhorst |
DATE | 11 |
| 2024 | REBECCA: Reconfigurable Heterogeneous Highly Parallel Processing Platform for Safe and Secure AI
Andreas Brokalakis, Iakovos Mavroidis, Konstantinos Georgopoulos, Pavlos Malakonakis, Konstantinos Harteros, Dimitris Andronikou, Yannis Galanomatis, Charalampos Savvakos, Grigorios Chrysos 0001, Sotiris Ioannidis, Ioannis Papaefstathiou |
DSD | 9 |
| 2022 | Assessing the Effectiveness of Active Fences Against SCAs for Multi-Tenant FPGAsabstractThe rising use of FPGAs, in the context of cloud computing, has created security concerns. Previous works have shown that malicious users can implement voltage fluctuation sensors and mount successful power analysis attacks against cryptographic algorithms that share the same Power Distribution Network (PDN). So far, masking and hiding schemes are the two main mitigation strategies against such attacks and previous work has shown that the use of an active fence of Ring Oscillators (ROs) holds the potential for constituting an effective hiding countermeasure if placed between two adversary users. Nevertheless, developing an effective proposition against remote Side-Channel Attacks (SCAs) remains an open research topic. This work presents the mapping of an intra-FPGA adversary scenario on a Xilinx UltraScale+ MPSoC to assess the effectiveness of the Ring Oscillator active fence countermeasure. We compare different active fence configurations, with a varying number of Ring Oscillators, while using a new, resource efficient, activation method aiming at the achievement of noise injection hiding. The results show that by using our active fence scheme, which exhibits lower area overhead and lower power consumption than the algorithm under attack, the side-channel leakage is reduced to such a degree that the amount of traces that need to be collected for a successful attack is more than ten times higher compared to no fence present. Moreover, this work presents qualitative results that FPGA cloud providers can consider in order to assess the benefits gained through the deployment of active fence mechanisms within their platforms for multi-tenant services. Christos Diktopoulos, Konstantinos Georgopoulos, Andreas Brokalakis, Georgios Christou, Grigorios Chrysos 0001, Ioannis Morianos, Sotiris Ioannidis |
FPL | 5 |
| 2020 | RAiSD-X: A Fast and Accurate FPGA System for the Detection of Positive Selection in Thousands of GenomesabstractDetecting traces of positive selection in genomes carries theoretical significance and has practical applications from shedding light on the forces that drive adaptive evolution to the design of more effective drug treatments. The size of genomic datasets currently grows at an unprecedented pace, fueled by continuous advances in DNA sequencing technologies, leading to ever-increasing compute and memory requirements for meaningful genomic analyses. The majority of existing methods for positive selection detection either are not designed to handle whole genomes or scale poorly with the sample size; they inevitably resort to a runtime versus accuracy tradeoff, raising an alarming concern for the feasibility of future large-scale scans. To this end, we present RAiSD-X, a high-performance system that relies on a decoupled access-execute processing paradigm for efficient FPGA acceleration and couples a novel, to our knowledge, sliding-window algorithm for the recently introduced μ statistic with a mutation-driven hashing technique to rapidly detect patterns in the data. RAiSD-X achieves up to three orders of magnitude faster processing than widely used software implementations, and more importantly, it can exhaustively scan thousands of human chromosomes in minutes, yielding a scalable full-system solution for future studies of positive selection in species of flora and fauna. Nikolaos Alachiotis 0001, Charalampos Vatsolakis, Grigorios Chrysos 0001, Dionisios N. Pnevmatikatos |
ACM Trans. Reconfigurable Technol. Syst. | 3 |
| 2019 | Data Stream Statistics Over Sliding Windows: How to Summarize 150 Million Updates Per Second on a Single NodeabstractTraditional data management systems map information using centralized and static data structures. Modern applications need to process in real time datasets much larger than system memory. To achieve this, they use dynamic entities that are updated with streaming input data over a sliding window. For efficient and high performance processing, approximate sketch synopses of input streams have been proposed as effective means for the summarization of streaming data over large sliding windows with probabilistic accuracy guarantees. This work presents a system-level solution to accelerate the Exponential Count-Min (ECM) sketch algorithm on reconfigurable technology. Different reconfigurable architectures for the sketch structure that correspond to different cost and performance tradeoffs are presented. We map the proposed system-level ECM sketch architectures to a high-end modern HPC platform to achieve guaranteed and best-effort update rates up to 150 and 180 million tuples per second respectively. We compare the performance of the implemented system against the best optimized multi-thread software alternative and show that our scalable full-system accelerators outperform software solutions by 5-7.5x for Virtex6 devices and in excess of 10x for current Ultrascale devices. Grigorios Chrysos 0001, Odysseas Papapetrou, Dionisios N. Pnevmatikatos, Apostolos Dollas, Minos N. Garofalakis |
FPL | 1 |
| 2018 | A decoupled access-execute architecture for reconfigurable acceleratorsabstractMapping computational intensive applications on reconfigurable technology for acceleration requires two main implementation parts: (a) the data plane, i.e., efficient interconnected units that accelerate processing, and (b) the access-plane, i.e., efficient ways to access data and transfer them to/from the accelerator. Data plane construction is well understood and mature tools -such as High Level Synthesis (HLS)- that produce efficient reconfigurable architectures exist. The access plane, however, is more challenging: data fetching for big-data and high-performance computing applications is even more complex and time consuming than processing. George Charitopoulos, Charalampos Vatsolakis, Grigorios Chrysos 0001, Dionisios N. Pnevmatikatos |
CF | 3 |
| 2018 | Accelerated Inference of Positive Selection on Whole GenomesabstractPositive selection is the tendency of beneficial traits to increase in prevalence in a population. Its detection carries theoretical significance and has practical applications, from shedding light on the forces that drive adaptive evolution to identifying drug-resistant mutations in pathogens. With next-generation sequencing producing a plethora of genomic data for population genetic analyses, the increased computational complexity of existing methods and/or inefficient memory management hinders the efficient analysis of large-scale datasets. To this end, we devise a system-level solution that couples a generic out-of-core algorithm for parsing genomic data with a decoupled access/execute accelerator architecture, thereby providing a method-independent infrastructure for the rapid and scalable inference of positive selection. We employ a novel detection mechanism that mostly relies on integer arithmetic operations, which fit well to FPGA fabric, while yielding qualitatively superior results than current state-of-the-art methods. We deploy a high-end system that pairs Hybrid Memory Cube with a mid-range FPGA, forming a high-throughput streaming accelerator that achieves 751x, 62x, and 20x faster analyses of simulated genomes than the widely used software tools SweepFinder2 (1 thread), OmegaPlus (40 threads), and SweeD (40 threads), respectively. Importantly, our solution can scan thousands of human genomes and millions of genetic polymorphisms (1000 Genomes dataset, 5,008 samples) in a matter of hours, requiring between 4 and 22 minutes per autosome, depending on the chromosomal length. Nikolaos Alachiotis 0001, Charalampos Vatsolakis, Grigorios Chrysos 0001, Dionisios N. Pnevmatikatos |
FPL | 3 |
| 2017 | A generic high throughput architecture for stream processingabstractStream join is a fundamental and computationally expensive data mining operation for relating information from different data streams. This paper presents two FPGA-based architectures that accelerate stream join processing. The proposed hardware-based systems were implemented on a multi-FPGA hybrid system with high memory bandwidth. The experimental evaluation shows that our proposed systems can outperform a software-based solution that runs on a high-end, 48-core multiprocessor platform by at least one order of magnitude. In addition, the proposed solutions outperform any other previously proposed hardware-based or software-based solutions for stream join processing. Finally, our proposed hardware-based architectures can be used as generic templates to map stream processing algorithms on reconfigurable logic, taking into consideration real-world challenges and restrictions. Christos Rousopoulos, Ektoras Karandeinos, Grigorios Chrysos 0001, Apostolos Dollas, Dionisios N. Pnevmatikatos |
FPL | 3 |
| 2016 | mCluster: A Software Framework for Portable Device-Based Volunteer ComputingabstractRecent market forecasts predict that the portable computing trend will vastly spread, as by 2020 there will bemore than 3 billion LTE device users worldwide. Motivated by this fact, many companies and research institutes have already launched research projects that utilize portable devices, voluntarily provided by users, to perform the required computations. Many such projects employ Berkeley's BOINC middleware, since it can support a large variety of stationary and mobile devices. However, currently available BOINC high-level APIs, either do not support portable devices or lack advanced processing capabilities (such as inter-node task dependencies) and/or easiness of use. To resolve these issues, we propose the mCluster software framework for application execution powered by the BOINC middleware on portable devices. mCluster adopts a task-based programming model that requires simple, pragma-based annotations of the application software, in order to dynamically resolve task dependencies. To evaluate our framework, we have have mapped a scientific application from the neuroscience domain on an small-scaled network of portable devices. mCluster significantly reduces the required programming effort and complexity to efficiently map BOINC-powered applications with task dependencies on portable devices compared to previous approaches. Dimitris Theodoropoulos 0001, Grigorios Chrysos 0001, Iosif Koidis, George Charitopoulos, Emmanouil Pissadakis, Antonis Varikos, Dionisios N. Pnevmatikatos, Georgios Smaragdos, Christos Strydis, Nikolaos A. Zervos |
CCGrid | 2 |
| 2016 | An FPGA-based high-throughput stream join architectureabstractStream join is a fundamental operation that combines information from different high-speed and high-volume data streams. This paper presents an FPGA-based architecture that maps the most performance-efficient stream join algorithm, i.e. ScaleJoin, to reconfigurable logic. The system was fully implemented on a Convey HC-2ex hybrid computer and the experimental performance evaluation shows that the proposed system outperforms by up to one order of magnitude the corresponding fully optimized parallel software-based solution running on a high-end 48-core multiprocessor platform. The proposed architecture can be used as a generic template for mapping stream processing algorithms to reconfigurable logic, taking into consideration real-world challenges. Charalabos Kritikakis, Grigorios Chrysos 0001, Apostolos Dollas, Dionisios N. Pnevmatikatos |
FPL | 2 |
| 2014 | HPC-gSpan: An FPGA-based parallel system for frequent subgraph miningabstractGraph mining is an important research area within the domain of data mining. One of the most challenging tasks of graph mining is frequent subgraph mining. This work presents the first FPGA-based implementation, to the best of our knowledge, of the most efficient and well-known algorithm for the Frequent Subgraph Mining (FSM) problem, i.e. gSpan. The proposed system, named High Performance Computing-gSpan (HPC-gSpan), achieves manyfold speedup vs. the official software solution of the gboost library when executed on a high-end CPU for various real-world datasets. Athanasios Stratikopoulos, Grigorios Chrysos 0001, Ioannis Papaefstathiou, Apostolos Dollas |
FPL | 2 |
| 2013 | HC-CART: A parallel system implementation of data mining classification and regression tree (CART) algorithm on a multi-FPGA systemabstractData mining is a new field of computer science with a wide range of applications. Its goal is to extract knowledge from massive datasets in a human-understandable structure, for example, the decision trees. In this article we present an innovative, high-performance, system-level architecture for the Classification And Regression Tree (CART) algorithm, one of the most important and widely used algorithms in the data mining area. Our proposed architecture exploits parallelism at the decision variable level, and was fully implemented and evaluated on a modern high-performance reconfigurable platform, the Convey HC-1 server, that features four FPGAs and a multicore processor. Our FPGA-based implementation was integrated with the widely used “rpart” software library of the R project in order to provide the first fully functional reconfigurable system that can handle real-world large databases. The proposed system, named HC-CART system, achieves a performance speedup of up to two orders of magnitude compared to well-known single-threaded data mining software platforms, such as WEKA and the R platform. It also outperforms similar hardware systems which implement parts of the complete application by an order of magnitude. Finally, we show that the HC-CART system offers higher performance speedup than some other proposed parallel software implementations of decision tree construction algorithms. Grigorios Chrysos 0001, Panagiotis Dagritzikos, Ioannis Papaefstathiou, Apostolos Dollas |
ACM Trans. Archit. Code Optim. | 1 |
| 2012 | Opportunities from the use of FPGAs as platforms for bioinformatics algorithmsabstractThis paper presents an in-depth look of how FPGA computing can offer substantial speedups in the execution of bioinformatics algorithms, with specific results achieved to date for a broad range of algorithms. Examples and case studies are presented for sequence comparison (BLAST, CAST), multiple sequence alignment (MAFFT, T-Coffee), RNA and protein secondary structure prediction (Zuker, Predator), gene prediction (Glimmer/GlimmerHMM) and phylogenetic tree computation (RAxML), running on mainstream FPGA technologies as well as high-end FPGA-based systems (Convey HC1, BeeCube). This work also presents technological and other obstacles that need to be overcome in order for FPGA computing to become a mainstream technology in Bioinformatics. Grigorios Chrysos 0001, Euripides Sotiriades, Christos Rousopoulos, Apostolos Dollas, Agathoklis Papadopoulos, Ioannis Kirmitzoglou, Vasilis J. Promponas, Theocharis Theocharides, George Petihakis 0001, Jacques Lagnel, Panagiotis Vavylis, George Kotoulas |
BIBE | 1 |
| 2011 | Parallel accelerators for GlimmerHMM bioinformatics algorithmabstractIn the last decades there is an exponential growth in the amount of genomic data that need to be analyzed. A very important problem in biology is the extraction of the biologically functional genomic DNA from the actual genome of the organisms. There have been proposed many computational biology algorithms that solve the gene finding problem which utilize various approaches; GlimmerHMM is considered one of the most efficient such algorithms. This paper presents two different accelerators for the GlimmerHMM algorithm. One of them is implemented on a modern FPGA platform exploiting the parallelism that reconfigurable logic offers and the other one utilizes a GPU (Graphic Processing Unit) taking advantage of a highly multithreaded operational environment. The performance of the implemented systems is compared against the one achieved when the official distribution of the algorithm is executed on a high-end multi-core server; the speedup initiated, for the most compute intensive part, is up to 200× for the FPGA-based system and up to 34× for the GPU-based system. Nafsika Chrysanthou, Grigorios Chrysos 0001, Euripides Sotiriades, Ioannis Papaefstathiou |
DATE | 2 |
| 2011 | Architecture, Design, and Experimental Evaluation of a Lightfield Descriptor Depth Buffer Algorithm on Reconfigurable Logic and on a GPUabstractThe Lightfield descriptor method for 3D computer graphics offers the highest quality object retrieval from a database at the expense of higher storage and computational cost vs. other methods. This paper presents two special purpose architectures, based on FPGAs and GPUs, for the depth buffer extraction algorithm which is used by the Light field Descriptor method. The two architectures were fully designed and implemented in hardware on a Virtex 5 FPGA Device and on a GeForce GPU. The FPGA-based design offers a measured average speedup of 50x vs. software. The corresponding GPU results were by comparison less promising, but still better than software solutions. Results reported in this paper are from actual runs on hardware. Matina Lakka, Grigorios Chrysos 0001, Ioannis Papaefstathiou, Apostolos Dollas |
FCCM | 2 |
| 2011 | Novel and Highly Efficient Reconfigurable Implementation of Data Mining Classification TreeabstractThe available e-data throughout the Web are growing at such a high rate that data mining on the web is considered the biggest challenge of information technology. As a result it is crucial to find new and innovative ways for classifying and mining those huge amounts of data. In this paper we present an implementation of a state-of-the-art data mining algorithm on a modern FPGA. This is one of the first approaches utilizing the resources of an FPGA to accelerate certain very CPU intensive data-mining/data classification schemes and our real-world results from actual runs on hardware demonstrate that it is a highly promising one. In particular, our FPGA-based system achieves, depending on the data classified, a speedup from 4x and up to 50x (on average 25x) when compared with a state-of-the art multi-core CPU, including I/O overhead. Grigorios Chrysos 0001, Panagiotis Dagritzikos, Ioannis Papaefstathiou, Apostolos Dollas |
FPL | 1 |
| 2010 | Reconfigurable Systems for the Zuker and Predator Algorithms for Secondary Structure Prediction of Genetic DataabstractSecondary structure prediction is a compute-intensive task that is used in many bioinformatics applications. In this paper we have selected two of the most well-known secondary structure prediction algorithms, the Predator and the Zuker algorithm, and we present two FPGA-based systems that implement them. Also, this paper presents different schemes of data reuse and data organization of structure prediction systems to avoid the data I/O bottleneck. The speedup of the execution time is at least 37x for the Predator method and 3x for the Zuker method compared to the corresponding software implementations. Finally, this paper shows that the exploitation of FPGA capabilities offers high performance systems that can be used by the bioinformatics community. Miltiadis Smerdis, Panagiotis Dagritzikos, Grigorios Chrysos 0001, Euripides Sotiriades, Apostolos Dollas |
FPL | 3 |
| 2009 | Design and implementation of a database filter for BLAST accelerationabstractBLAST is a very popular computational biology algorithm. Since it is computationally expensive it is a natural target for acceleration research, and many reconfigurable architectures have been proposed offering significant improvements. In this paper we approach the same problem with a different approach: we propose a BLAST algorithm preprocessor that efficiently identifies the portions of the database that must be processed by the full algorithm in order to find the complete set of desired results. We show that this preprocessing is feasible and quick, and requires minimal FPGA resources, while achieving a significant reduction in the size of the database that needs to be processed by BLAST. We also determine the parameters under which prefiltering is guaranteed to identify the same set of solutions as the original NCBI software. We model our preprocessor in VHDL and implement it in reconfigurable architecture. To evaluate the performance, we use a large set of datasets and compare against the original (NCBI) software. Prefiltering is able to determine that between 80 and 99.9% of the database will not produce matches and can be safely ignored. Processing only the remaining portions using software such as NCBI-BLAST improves the system performance (reduces execution time) by 3 to 15 times. Since our prefiltering technique is generic, it can be combined with any other software or reconfigurable acceleration technique. Panagiotis Afratis, Constantinos Galanakis, Euripides Sotiriades, Georgios-Grigorios Mplemenos, Grigorios Chrysos 0001, Ioannis Papaefstathiou, Dionisios N. Pnevmatikatos |
DATE | 5 |
| 2009 | A FPGA based coprocessor for gene finding using Interpolated Markov Model (IMM)abstractAn important biology problem is the decoding of the DNA and the extraction of useful genetic information. There are many bioinformatics algorithms that try to solve the gene finding problem and one of the most efficient is the Glimmer algorithm. In this paper, we present a hardware architecture that implements the Glimmer algorithm. The architecture was developed specifically for the capabilities of present-day FPGAs. In addition, this paper presents an efficient hardware method to construct a huge but very sparse lookup table by taking advantage the tree-like structure of memories. Grigorios Chrysos 0001, Euripides Sotiriades, Ioannis Papaefstathiou, Apostolos Dollas |
FPL | 1 |
| 2008 | A rate-based prefiltering approach to blast accelerationabstractDNA sequence comparison and database search have evolved in the last years as a field of strong competition between several reconfigurable hardware computing groups. In this paper we present a BLAST preprocessor that efficiently marks the parts of the database that may produce matches. Our prefiltering approach offers significant reduction in the size of the database that needs to be fully processed by BLAST, with a corresponding reduction in the run-time of the algorithm. We have implemented our architecture, evaluated its effectiveness for a variety of databases and queries, and compared its accuracy against the original NCBI Blast implementation. We have found that prefiltering offers at least a factor of 5 and up to 3 orders of magnitude reduction in the database space that needs to be fully searched. Due to its prefiltering nature, our approach can be combined with all major reconfigurable acceleration architectures that have been presented up to date. Panagiotis Afratis, Euripides Sotiriades, Grigorios Chrysos 0001, Sotiria Fytraki, Dionisios N. Pnevmatikatos |
FPL | 3 |
| 2007 | An Integrated Video Compression, Encryption and Information Hiding Architecture based on the SCAN Algorithm and the Stretch TechnologyabstractSCAN is a class of formal languages for compression, encryption and information hiding. We have previously studied and reported separate hardware implementations of SCAN compression and encryption. This paper presents initial results on the design of a complete single-chip system for the SCAN compression, encryption and information hiding algorithm using the stretch technology with reconfigurable and fixed resources. The result is a simple, low cost, embeddable core combining all three operations seamlessly and the design was fully mapped to the stretch technology. Grigorios Chrysos 0001, Apostolos Dollas, Nikolaos G. Bourbakis, J. Sukarno Mertoguno |
FCCM | 1 |
| 2001 | Architecture and Application of PLATO, A Reconfigurable Active Network Platform
Apostolos Dollas, Dionisios N. Pnevmatikatos, Nikolaos Aslanides, Stamatios Kavvadias, Euripides Sotiriades, Sotirios Zogopoulos, Kyprianos Papademetriou, Grigorios Chrysos 0001, Konstantinos Harteros, Emmanouel Antonidakis, Nikolaos Petrakis |
FCCM | 8 |