Publications

Research Publications

2025

  1. Cloudy with a Chance of Anomalies: Dynamic Graph Neural Network for Early Detection of Cloud Services’ User Anomalies
    2025
    Revital Marbel, Yanir Cohen, Ran Dubin, Amit Dvir, and Chen Hajaj
    Proceedings of the 34th International Conference on Computer Communications and Networks
  2. Optimized File Type Detection and One-Shot Reclassification Model
    2025
    Simona Lisker, Ayelet Botman, Chen Hajaj, Ran Dubin, and Amit Dvir
    Proceedings of the IEEE International Conference on Communications
  3. A New D-MAGIC: Dynamic Model for Cybersecurity Attack Detection Using GNNs into Clustering
    2025
    Zohar Simhon, Matan Weiss, Chen Hajaj, Revital Marbel, Ran Dubin, and Amit Dvir
    Proceedings of the IEEE International Conference on Communications
  4. Enhancing Encrypted Internet Traffic Classification Through Advanced Data Augmentation Techniques
    2025
    Yehonatan Zion, Porat Aharon, Ran Dubin, Amit Dvir, and Chen Hajaj
    Proceedings of the IEEE International Conference on Communications
  5. PQClass: Classification of Post-Quantum Encryption Applications in Internet Traffic
    2025
    Angelos Marnerides, Chen Hajaj, Revital Marbel, Ran Dubin, and Amit Dvir
    Proceedings of the IEEE International Conference on Communications
  6. Sentiment Analysis of Student-Tutor Interactions in VR Design Crits
    2025
    Hadas Sopher, Chen Hajaj, and John S Gero
    The Association for Computer-Aided Architectural Design Research in Asia (CAADRIA)
  7. A Classification-by-Retrieval Framework for Few-Shot Anomaly Detection to Detect API Injection
    2025
    Udi Aharon, Ran Dubin, Amit Dvir, and Chen Hajaj
    Computers & Security
  8. Predicting Onset and Progression of Neurodegenerative Diseases Using Blood Test Data and Machine Learning Models
    2025
    Amir Glik, Chen Hajaj, Orit Rephaeli, and Anat Goldstein

2024

  1. Phenotypical Characteristics of Nontuberculous Mycobacterial Infection in Patients with Bronchiectasis
    2024
    Assaf Frajman, Shimon Izhakian, Ori Mekiten, Ori Hadar, Ariel Lichtenstadt, Chen Hajaj, Shon Shchori, Moshe Heching, Dror Rosengarten, and Mordechai R Kramer
    Respiratory Research
  2. Warm Recommendation: Enhancing Cold Start Recommendations Using Multimodal Product Representations
    2024
    Anat Goldstein, Amit Alony, and Chen Hajaj
    International Conference on Information Systems (ICIS)
  3. The Art of Time-Bending: Data Augmentation and Early Prediction for Efficient Traffic Classification
    2024
    Chen Hajaj, Porat Aharon, Ran Dubin, and Amit Dvir
    Expert Systems with Applications
  4. CBR–Boosting Adaptive Classification By Retrieval of Encrypted Network Traffic with Out-of-Distribution
    2024
    Amir Lukach, Ran Dubin, Amit Dvir, and Chen Hajaj
    arXiv preprint arXiv:2403.11206
  5. Cloudy with a Chance of Anomalies: Dynamic Graph Neural Network for Early Detection of Cloud Services’ User Anomalies
    2024
    Revital Marbel, Yanir Cohen, Ran Dubin, Amit Dvir, and Chen Hajaj
    arXiv preprint arXiv:2409.12726
  6. Exploring the Role of Sentiment in Tutor-Student Interaction. The Case Study of CS and Architecture Formative Studio Critiques
    2024
    Hadas Sopher, Chen Hajaj, and John S Gero
    2024 IEEE Frontiers in Education Conference (FIE)
  7. Enhancing Encrypted Internet Traffic Classification Through Advanced Data Augmentation Techniques
    2024
    Yehonatan Zion, Porat Aharon, Ran Dubin, Amit Dvir, and Chen Hajaj
    arXiv preprint arXiv:2407.16539
  8. Few-Shot API Attack Detection: Overcoming Data Scarcity with GAN-Inspired Learning
    2024
    Udi Aharon, Revital Marbel, Ran Dubin, Amit Dvir, and Chen Hajaj
    arXiv preprint arXiv:2405.11258
  9. Extending Limited Datasets with GAN-Like Self-Supervision for SMS Spam Detection
    2024
    Or Haim Anidjar, Revital Marbel, Ran Dubin, Amit Dvir, and Chen Hajaj
    Computers & Security
  10. OSF-EIMTC: An Open-Source Framework for Standardized Encrypted Internet Traffic Classification
    2024
    Ofek Bader, Adi Lichy, Amit Dvir, Ran Dubin, and Chen Hajaj
    Computer Communications
  11. Hidden in Time, Revealed in Frequency: Spectral Features and Multiresolution Analysis for Encrypted Internet Traffic Classification
    2024
    Nathan Dillbary, Roi Yozevitch, Amit Dvir, Ran Dubin, and Chen Hajaj
    2024 IEEE 21st Consumer Communications & Networking Conference (CCNC)
  12. Measuring Flight-Destination Similarity: A Multidimensional Approach
    2024
    Anat Goldstein, and Chen Hajaj
    Expert Systems with Applications
  13. The Sound of Emotions: An Artificial Intelligence Approach to Predicting Emotions from Musical Selections
    2024
    Ron Simha Hirschprung, Ori Leshman, and Chen Hajaj
    Available at SSRN 4656595
  14. Revolutionizing Our Way to Better Classifiers: Leveraging Synthetic Data with Generative Models for Encrypted Network Traffic Classification
    2024
    Yehonatan Zion, Chen Hajaj, Amit Dvir, Gil Ben-Artzi, Shahar Mahpod, and Ran Dubin
    Available at SSRN 4654236

2023

  1. Speech and Multilingual Natural Language Framework for Speaker Change Detection and Diarization
    2023
    Or Haim Anidjar, Yannick Estève, Chen Hajaj, Amit Dvir, and Itshak Lapidot
    Expert Systems with Applications
  2. Online Temporary Learning Groups in Higher Education–Interactions, Compensation, and Maximisation of Achievements in an Israeli Case Study
    2023
    Uzi Ben-Shalom, Chen Hajaj, Nitza Davidovitch, and Corinne Berger
    Journal of Education Culture and Society
  3. Breaking the Structure of MaMaDroid
    2023
    Harel Berger, Amit Dvir, Enrico Mariconti, and Chen Hajaj
    Expert Systems with Applications
  4. Adversarial Examples for Captcha Generation Adversarial Machine Learning for Social Good
    2023
    Chen Hajaj, and Meir Litman
    Available at SSRN 4608639
  5. Detecting Parallel Covert Data Transmission Channels in Video Conferencing Using Machine Learning
    2023
    Ofir Joseph, Avshalom Elmalech, and Chen Hajaj
    Electronics
  6. When a RF Beats a CNN and GRU, Together—A Comparison of Deep Learning and Classical Machine Learning Approaches for Encrypted Malware Traffic Classification
    2023
    Adi Lichy, Ofek Bader, Ran Dubin, Amit Dvir, and Chen Hajaj
    Computers & Security
  7. Protein Intake and Clinical Outcomes of Enterally Fed Critically Ill Patients
    2023
    O Raphaeli, L Statlander, C Hajaj, I Bendavid, and Pierre Singer
    Clinical Nutrition ESPEN
  8. Using Machine-Learning to Assess the Prognostic Value of Early Enteral Feeding Intolerance in Critically Ill Patients: A Retrospective Study
    2023
    Orit Raphaeli, Liran Statlender, Chen Hajaj, Itai Bendavid, Anat Goldstein, Eyal Robinson, and Pierre Singer
    Nutrients

2022

  1. SimCSE for Encrypted Traffic Detection and Zero-Day Attack Detection
    2022
    Rotem Bar, and Chen Hajaj
    IEEE Access
  2. MaMaDroid2.0–The Holes of Control Flow Graphs
    2022
    Harel Berger, Chen Hajaj, Enrico Mariconti, and Amit Dvir
    arXiv preprint arXiv:2202.13922
  3. Problem-Space Evasion Attacks in the Android OS: A Survey
    2022
    Harel Berger, Chen Hajaj, and Amit Dvir
    arXiv preprint arXiv:2205.14576
  4. Do You Think You Can Hold Me? The Real Challenge of Problem-Space Evasion Attacks
    2022
    Harel Berger, Amit Dvir, Chen Hajaj, and Rony Ronen
    arXiv preprint arXiv:2205.04293
  5. The Hidden Conversion Funnel of Mobile vs. Desktop Consumers
    2022
    Anat Goldstein, and Chen Hajaj
    Electronic Commerce Research and Applications
  6. Less Is More: Robust and Novel Features for Malicious Domain Detection
    2022
    Chen Hajaj, Nitay Hason, and Amit Dvir
    Electronics
  7. MalDIST: From Encrypted Traffic Classification to Malware Traffic Detection and Classification
    2022
    Ofek Bader, Adi Lichy, Chen Hajaj, Ran Dubin, and Amit Dvir
    2022 IEEE 19th annual consumer communications & networking conference (CCNC)
  8. Using the Cardio-Vascular Index (CVRI) to Predict Mortality in Septic Shock
    2022
    O Raphaeli, I Bendavid, C Hajaj, L Statlander, A Goldstein, E Chen, P Singer, and U Gabbay
    ISICEM

2021

  1. Crystal Ball: From Innovative Attacks to Attack Effectiveness Classifier
    2021
    Harel Berger, Chen Hajaj, Enrico Mariconti, and Amit Dvir
    IEEE Access
  2. Robust Coordination in Adversarial Social Networks: From Human Behavior to Agent-Based Modeling
    2021
    Chen Hajaj, Zlatko Joveski, Sixie Yu, and Yevgeniy Vorobeychik
    Network Science
  3. Prediction Model for the Spread of the COVID-19 Outbreak in the Global Environment
    2021
    Ron S Hirschprung, and Chen Hajaj
    Heliyon
  4. A Thousand Words Are Worth More Than One Recording: Word-Embedding Based Speaker Change Detection
    2021
    Or Haim Anidjar, Itshak Lapidot, Chen Hajaj, and Amit Dvir
    Interspeech
  5. Hybrid Speech and Text Analysis Methods for Speaker Change Detection
    2021
    Or Haim Anidjar, Itshak Lapidot, Chen Hajaj, Amit Dvir, and Issachar Gilad
    IEEE/ACM Transactions on Audio, Speech, and Language Processing
  6. PCL: Packet Classification with Limited Knowledge
    2021
    Vitalii Demianiuk, Chen Hajaj, and Kirill Kogan
    IEEE INFOCOM 2021-IEEE Conference on Computer Communications
  7. Feeding Intolerance as a Predictor of Clinical Outcomes in Critically Ill Patients: A Machine Learning Approach
    2021
    O Raphaeli, C Hajaj, I Bendavid, A Goldstein, E Chen, and P Singer
    Clinical Nutrition ESPEN
  8. Using machine learning to support early prediction of feeding intolerance in critically ill patients
    2021
    O Raphaeli, C Hajaj, I Bendavid, A Goldstein, E Chen, and P Singer
    ESICM LIVES

2020

  1. Evasion Is Not Enough: A Case Study of Android Malware
    2020
    Harel Berger, Chen Hajaj, and Amit Dvir
    arXiv preprint arXiv:2003.14123
  2. Encrypted Video Traffic Clustering Demystified
    2020
    Amit Dvir, Angelos K Marnerides, Ran Dubin, Nehor Golan, and Chen Hajaj
    Computers & Security
  3. Robust Machine Learning for Encrypted Traffic Classification
    2020
    Jonathan Muehlstein, Yehonatan Zion, Ofir Pele, Chen Hajaj, Ran Dubin, and Amit Dvir
    CoRR
  4. Evasion Is Not Enough: A Case Study of Android Malware
    2020
    Harel Berger, Chen Hajaj, and Amit Dvir
    International symposium on cyber security cryptography and machine learning
  5. Robust Malicious Domain Detection
    2020
    Nitay Hason, Amit Dvir, and Chen Hajaj
    Cyber Security Cryptography and Machine Learning: Fourth International Symposium, CSCML 2020, Be’er Sheva, Israel, July 2–3, 2020, Proceedings 4

2019

  1. Adversarial Coordination on Social Networks
    2019
    Chen Hajaj, Sixie Yu, Zlatko Joveski, and Yevgeniy Vorobeychik
    Proceedings of the 18th International Conference on Autonomous Agents and Multiagent Systems
  2. Improving Robustness of ML Classifiers Against Realizable Evasion Attacks Using Conserved Features
    2019
    Liang Tong, Bo Li, Chen Hajaj, Chaowei Xiao, Ning Zhang, and Yevgeniy Vorobeychik
    28th USENIX Security Symposium (USENIX Security 19)

2018

  1. Adversarial task assignment
    2018
    Chen Hajaj, and Yevgeniy Vorobeychik
    International Joint Conference on Artificial Intelligence
  2. A crowdsourcing framework for medical data sets
    2018
    Cheng Ye, Joseph Coco, Anna Epishova, Chen Hajaj, Henry Bogardus, Laurie Novak, Joshua Denny, Yevgeniy Vorobeychik, Thomas Lasko, Bradley Malin, and  others
    AMIA Summits on Translational Science Proceedings

2017

  1. Non-Cooperative Team Formation and a Team Formation Mechanism
    2017
    Matthew Chambers, Chen Hajaj, Greg Leo, Jian Lou, Martin Linden, Yevgeniy Vorobeychik, and Myrna H Wooders
    Available at SSRN 3054771
  2. Enhancing Comparison Shopping Agents Through Ordering and Gradual Information Disclosure
    2017
    Chen Hajaj, Noam Hazon, and David Sarne
    Autonomous Agents and Multi-Agent Systems
  3. Selective Opportunity Disclosure at the Service of Strategic Information Platforms
    2017
    Chen Hajaj, and David Sarne
    Autonomous Agents and Multi-Agent Systems
  4. Enhancing Crowdworkers’ Vigilance
    2017
    Avshalom Elmalech, David Sarne, Esther David, and Chen Hajaj
    Twenty-Sixth International Joint Conference on Artificial Intelligence (IJCAI-17)
  5. Agent-Mediated Electronic Commerce. Designing Trading Strategies and Mechanisms for Electronic Markets
    2017
    Sofia Ceppi, Esther David, Chen Hajaj, Valentin Robu, and Ioannis A Vetsikas

2016

  1. Robust Machine Learning for Encrypted Traffic Classification
    2016
    Amit Dvir, Yehonatan Zion, Jonathan Muehlstein, Ofir Pele, Chen Hajaj, and Ran Dubin
    arXiv preprint arXiv:1603.04865
  2. Extending Workers’ Attention Span Through Dummy Events
    2016
    Avshalom Elmalech, David Sarne, Esther David, and Chen Hajaj
    Proceedings of the AAAI Conference on Human Computation and Crowdsourcing
  3. Intelligent Mechanisms for Platforms in Modern Markets
    2016
    Chen Hajaj

2015

  1. Improving Comparison Shopping Agents’ Competence Through Selective Price Disclosure
    2015
    Chen Hajaj, Noam Hazon, and David Sarne
    Electronic Commerce Research and Applications
  2. Automatic Anatomical Shape Correspondence and Alignment Using Mesh Features
    2015
    Tal Darom, Yaniv Gur, Chen Hajaj, and Yosi Keller
    Biomedical Imaging (ISBI), 2015
  3. Strategy-Proof and Efficient Kidney Exchange Using a Credit Mechanism
    2015
    Chen Hajaj, John P Dickerson, Avinatan Hassidim, Tuomas Sandholm, and David Sarne
    In proceedings of the Twenty-Ninth AAAI Conference on Artificial Intelligence

2014

  1. Advanced Service Schemes for a Self-Interested Information Platform
    2014
    Chen Hajaj, David Sarne, and Lea Perets
    Proceedings of the 2014 international conference on Autonomous agents and multi-agent systems
  2. Ordering Effects and Belief Adjustment in the Use of Comparison Shopping Agents
    2014
    Chen Hajaj, Noam Hazon, and David Sarne
    Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence (AAAI 2014)
  3. Strategic Information Platforms: Selective Disclosure and the Price of Free
    2014
    Chen Hajaj, and David Sarne
    Proceedings of the Fifteenth ACM conference on Economics and Computation

2013

  1. Search More, Disclose Less
    2013
    Chen Hajaj, Noam Hazon, David Sarne, and Avshalom Elmalech
    In proceedings of the Twenty-Seventh AAAI Conference on Artificial Intelligence

2012

  1. Three Dimensional Group Registration of Mesh Objects
    2012
    Chen Hajaj