Adopt a Loggerhead sea turtle

I am an Assistant Professor at the Electrical and Computer Engineering Department, University of Patras, from which I also received a PhD and BSc. My research is related to the design and evaluation of information systems.

Published papers in top-ranked scientific venues, which received awards, and (co-) supervised Ph.D. and M.Sc. students. Long-standing professional experience as a project coordinator and principal investigator in EU-funded and National research projects. Fluent in German, English and Greek.

Email: fidas AT upatras.gr :: LinkedIn Profile: https://www.linkedin.com/in/fidas
Find me also at
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[New Research Project - July 2021] Excited to receive a research grant of €194,295.00, from the Hellenic Foundation for Research and Innovation (H.F.R.I.), to Support Faculty Members & Researchers in the field of Engineering Sciences and Technology.

The award will be used to extend our laboratory (Interactive Technologies Lab) research infrastructure with state-of-the-art electroencephalography (EEG) and eye-tracking devices and provide financial support for two (2) new PhD students. The project aims to suggest innovative user interface design and interaction workflows based on an AI-driven and electroencephalography (EEG) based framework for real-time modelling of human cognitive abilities.
Interested PhD candidates with a background on Electrical and Computer Engineering, Computer Science, and other relevant fields are welcome to send their CV's by September 30, 2021 to the following address: fidas@upatras.gr

[New Publications - June 2021] Happy about our three new paper publication at the 18th IFIP TC.13 International Conference on Human-Computer Interaction (INTERACT 2021), entitled "A Field Dependence-Independence Perspective on Eye Gaze Behavior within Affective Activities", "An Empirical Study of Picture Password Composition on Smartwatches" and "Understanding Insider Attacks in Personalized Picture Password Schemes".

[New EU Project - March 2021] I am honored to act as a Project Coordinator and Principal Investigator of the EU project TRUSTID that has been approved by the European Commission with a total funding of €291,310. The proposal was submitted in collaboration with the University of Cyprus (Cyprus), the Institute of Systems and Robotics - University of Coimbra (Portugal) and Cognitive UX GmbH (Germany).

[New Lab Member - March 2021] I would like to welcome Mrs. Kyriaki Konstantina (MSc) to our lab (Interactive Technologies - HCI Group) who started her PhD studies on building an Eye Gaze and Electroencephalography Driven Framework for Human Memory Modeling.

[Workshop at ACM UMAP 2021 - January 2021] I am looking forward to running the 3rd edition of our workshop APPS 2021 - Adaptive and Personalized Privacy and Security, in conjunction with ACM UMAP 2021. Our special focus in 2021 will be on challenges and opportunities related to the Covid-19 outbreak on ensuring security and privacy of sensitive data and secure user interactions in online systems such as challenges for online distance learning, the need for touchless authentication, e-Government, e-Commerce, etc.

[New Publication - January 2021] Our paper entitled "From hot-spots towards experience-spots: Leveraging on users’ sociocultural experiences to enhance security in cued-recall graphical authentication" has been accepted at the International Journal of Human-Computer Studies.

[New Position - November 2020] I am thankful for spending the last years at the Department of Cutlural Heritage Management and New Technologies of the University of Patras. Many thanks to all my colleagues and supporting staff for a fruitful and joyful collaboration. I am very happy to join the Electrical and Computer Engineering Department of the University of Patras. I look forward to work with my new colleagues and students.

[Guest Editor of Special Issue - November 2020] I am the Guest Editor, together with Dr. Stella Sylaiou and Dr. George Pavlidis, of the Special Issue "Mixed Reality in Culture and Heritage" at the Heritage Journal. Please download the Call for Papers (.pdf)

[Best Paper Award - October 2020] We received the prestigious UMUAI James Chen award for best paper of 2019, for our paper entitled "A cognition-centered personalization framework for cultural heritage content". The User Modeling and User Adapted Interaction (UMUAI) James Chen Award is bestowed annually to the author(s) of the best paper of the year. The award has been donated by the Chen family in commemoration of James R. Chen.

[New Publication - March 2020] Our paper related to personalizing the user authentication process of information systems based on users' cross-cultural differences has been accepted at the ACM User Modeling, Adaptation and Personalization (UMAP 2020) papers' main program (23% acceptance rate). The work has been conducted in collaboration with the Shanghai Jiao Tong University.

[New Project - December 2019] I am enchanted that our project proposal "Development and production of augmented and virtual reality applications supporting narrative tours at the Tomato Industrial Museum "D. Nomikos" has been included for funding within the RESEARCH - CREATE - INNOVATE call. The proposal has been rated among the first 200 out of 2100 submissions (acceptance rate 10%).
The project proposes the production, presentation and promotion of a versatile cultural product that falls within the general context of the Museum's modern operation as cultural industry, thus linking academic research and innovation with entrepreneurship.

[New Publication - December 2019] Our paper related to improving the estimation of graphical password strength based on the interplay between image content familiarity and gaze-behaviour on image hotspots has been accepted at the ACM Intelligent User Interfaces (IUI 2020) papers' main program (16% acceptance rate).

[view more]


  • German Patent & Trade Mark Office (Deutsches Patent- und Markenamt): Method and apparatus for flexible user authentication based on individual human cognitive characteristics (Methode und vorrichtung zur flexiblen benutzerauthentifizierung basierend auf individuellen menschlichen kognitiven eigenschaften) – patent pending
  • Greek Industrial Property Organisation (Οργανισμός Βιομηχανικής Ιδιοκτησίας): Methods and tools to support and monitor in real time visitors of the World Wide Web (N. Patent No. 1004805.OVI, INT. CL G06F 17/60, g06f 15/163)

Honors and Awards

  • UMUAI James Chen Award for Best Paper of 2019 (November 2020)
    Research paper entitled "A Cognition-centered Personalization Framework for Cultural Heritage Content"
  • Seal of Excellence - Horizon 2020 Marie Skłodowska-Curie actions call H2020-MSCA-IF-2016
    For a high-quality project proposal in a highly competitive evaluation process, namely CogniPass – Cognition-based Personalised Authentication SchemeS [Seal of Excellence]
  • Best Paper Nomination Award and Honourable Mention at UMAP 2014 Conference (July 2014)
    Research paper entitled "A Personalisation Method based on Human Factors for Improving Usability of User Authentication Tasks"
  • Best Paper Award at SouthCHI 2013 Conference (July 2013)
    Research paper entitled "Towards the Personalization of CAPTCHA Mechanisms based on Individual Differences in Cognitive Processing"


Journals (Selected Publications)
Elsevier IJHCS
From hot-spots towards experience-spots: Leveraging on users' sociocultural experiences to enhance security in cued-recall graphical authentication
Constantinides, A., Fidas, C., Belk, M., Pietron, A., Han, T., Pitsillides, A.
International Journal of Human-Computer Studies, 149, Elsevier, 2021 - Impact Factor: 3.16
DOI: https://doi.org/10.1016/j.ijhcs.2021.102602
Springer UMUAI
A cognition-centered personalization framework for cultural heritage content
Raptis, G., Fidas, C., Katsini, C., Avouris, N.
User Modeling and User-Adapted Interaction (UMUAI). The Journal of Personalization Research, 29(1), 9-65, Springer, 2019 - Impact Factor: 4.68, James Chen Award for best paper of 2019
DOI: https://doi.org/10.1007/s11257-019-09226-7
Do game designers' decisions related to visual activities affect knowledge acquisition in cultural heritage games? An evaluation from a human cognitive processing perspective
Raptis, G., Fidas, C., Avouris, N.
ACM Journal on Computing and Cultural Heritage 12, 1, Article 4, ACM Press, 2019 - Impact Factor: 1.72
DOI: https://doi.org/10.1145/3292057
A human-cognitive perspective of users' password choices in recognition-based graphical authentication
Katsini, C., Fidas, C., Belk, M., Samaras, G., Avouris, N.
International Journal of Human–Computer Interaction, 35(19), 1800-1812, 2019, Taylor & Francis, 2019 - Impact Factor: 1.71
DOI: https://doi.org/10.1080/10447318.2019.1574057
Elsevier IJHCS
Effects of mixed-reality on players' behaviour and immersion in a cultural tourism game: A cognitive processing perspective
Raptis, G., Fidas, C.A., Avouris, N.
International Journal of Human-Computer Studies, 69-79, Elsevier, 2018 - Impact Factor: 3.16
DOI: https://doi.org/10.1016/j.ijhcs.2018.02.003
Elsevier CHB
The interplay between humans, technology and user authentication: a cognitive processing perspective
Belk M., Fidas C., Germanakos P., Samaras G.
Computers in Human Behavior, 76, 184-200, Elsevier, 2017 - Impact Factor: 5
DOI: https://doi.org/10.1016/j.chb.2017.06.042
Elsevier IJHCS
Do human cognitive differences in information processing affect preference and performance of captcha?
Belk M., Fidas C., Germanakos P., Samaras G.
International Journal of Human-Computer Studies, 84, 1-18, Elsevier, 2015 - Impact Factor: 3.16
DOI: http://dx.doi.org/10.1016/j.ijhcs.2015.07.002
Oxford Uni. Press
A personalized user authentication approach based on individual differences in information processing
Belk M., Fidas C., Germanakos P., Samaras G.
Interacting with Computers, 27(6), Oxford University Press, 2015 - Impact Factor: 1.03
DOI: https://doi.org/10.1093/iwc/iwu033
Elsevier Comp. Ed.
Heterogeneity of learning material in synchronous computer-supported collaborative modelling
Fidas, C.A., Komis, V., Tzanavaris, S., Avouris, N.
Computers and Education, 44(2), 135-154, Elsevier, 2005 - Impact Factor: 5.29
DOI: http://dx.doi.org/10.1016/j.compedu.2004.02.001
Education and Information Technologies
Computer-supported collaborative concept mapping: Study of synchronous peer interaction
Komis, V., Avouris, N., Fidas, C.
Education and Information Technologies, 7(2), 169-188, Springer, 2002
DOI: https://doi.org/10.1023/A%3A1020309927987
Conferences (Selected Publications in the last three years)
Fidas, C., Belk, M., Constantinides, C., Constantinides, A., Pitsillides, A. (2021). A field dependence-independence perspective on eye gaze behavior within affective activities, IFIP TC.13 International Conference on Human-Computer Interaction (INTERACT 2021), Springer (to appear)
Fidas, C., Belk, M., Portugal, D. Pitsillides, A. (2021). Privacy-preserving biometric-driven data for student identity management: Challenges and approaches, ACM User Modeling, Adaptation and Personalization (UMAP 2021), ACM Press (to appear)
Constantinides, A., Pietron, A., Belk, M., Fidas, C., Han, T., Pitsillides, A. (2020). A cross-cultural perspective for personalizing picture passwords, ACM User Modeling, Adaptation and Personalization (UMAP 2020), 43-52, ACM Press [https://doi.org/10.1145/3340631.3394859]
ACM IUI 2020
Constantinides, A., Belk, M., Fidas, C., Pitsillides, A. (2020). An eye gaze-driven metric for estimating the strength of graphical passwords based on image hotspots. ACM Intelligent User Interfaces (IUI 2020), ACM Press, 33-37 [https://doi.org/10.1145/3377325.3377537]
ACM CHI 2018
Katsini, C., Fidas, C., Raptis, G., Belk, M., Samaras, G., & Avouris, N. (2018). Influences of human cognition and visual behavior on password security during picture password composition. ACM SIGCHI Human Factors in Computing Systems (CHI 2018), ACM Press, paper 87 [https://doi.org/10.1145/3173574.3173661]


Project Coordinator and Principal Investigator

  • National Research Project Electroencephalography and Eye Gaze-driven Framework for Intelligent and Real-Time Human Cognitive Modelling (€194,295, 2022-2024, Project Coordinator, Principal Investigator). Funding Agency: Hellenic Foundation for Research and Innovation (H.F.R.I.)
  • EU Research Project TRUSTID: Intelligent and Continuous Online Student Identity Management for Improving Security and Trust in European Higher Education Institutions (€291,310, 2021-2023, Project Coordinator, Principal Investigator). Funding Agency: European Commission, Greek State Scholarships Foundation. Call: Strategic Partnerships in Response to the COVID-19 Situation: Partnerships for Digital Education Readiness in the field of Higher Education (KA226)
  • National Research Project D. Nomikos: Development and production of augmented and virtual reality applications supporting narrative tours at the Tomato Industrial Museum (€300,000, 2021-2023, Principal Investigator). Funding Agency: Research-Create-Innovate

Work Package Leader and Researcher, and Project Manager

  • H2020-SERUMS: Securing Medical Data in Smart Patient-Centric Healthcare Systems (2019-2021, WP5 - User Authentication and Trust) - http://serums-smartpatient.com/
  • FP7-CR-PLAY: Capture Reconstruct Play (2013-2016, WP5 Leader - Formative and Summative Evaluation) - http://www.cr-play.eu
  • FP7-SERIES: Seismic Engineering Research Infrastructures for European Synergies (2009-2013, Lead of Information Systems Architecture Design and Implementation) - http://www.series.upatras.gr
  • FP6-QALIBRA: Quality of life-integrated benefit and risk analysis web-based tool for assessing food safety and health benefits (2006-2010, Lead of Evaluation) - http://www.qalibra.eu
  • FP6 e-Ten-COMMODE: Collaborative modeling environment (2005-2006, Lead of Evaluation and Pilot Studies)
  • IST-MODELLINGSPACE: Space of ideas expression modeling and collaboration (2001-2004, Software Engineer)


CogniKit: An Extensible Tool for Human Cognitive Modeling based on Eye Gaze Analysis

In this work, we have designed and developed CogniKit, an extensible tool for human cognitive modeling. It is based on the analysis, classification and visualization of eye tracking data such as gaze points, fixation count and duration, saccades, gaze transition and stationary entropy, heat maps, areas of interests, etc. These are further processed, analyzed and classified for detecting higher level human cognitive factors such as cognitive processing styles and abilities. CogniKit comprises of two main components: i) a software application that collects and processes low- and high-level eye gaze data metrics in real-time; and ii) an extensible interactive workbench for storing, analyzing, classifying and visualizing the collected eye gaze data.

Relevant paper: ACM WI 2019, ACM IUI 2020

HoloPass: Picture Passwords in Mixed Reality

Mixed reality technologies embrace hand gesture-based interaction modalities, which can be leveraged by picture passwords, as they require users to draw secret gestures on a background image. In this work, we have designed and developed HoloPass, a novel mixed reality application that utilizes the Microsoft HoloLens device that allows users to directly interact with picture-based holograms in order to perform user authentication tasks. The current prototype was developed in Unity 3D, using C# and Microsoft's Mixed Reality Toolkit for HoloLens, and follows implementation guidelines of Microsoft Windows 10 Picture Gesture Authentication in which users draw three secret gestures on a background image that acts as a cue.

Relevant papers: ACM CHI 2019, INTERACT 2019

Security through Play: A Playful Interaction Design in Mixed Reality for Improving Graphical Password Security

This work aims at scaffolding end-users in improving the security of graphical passwords through a playful interaction design in mixed reality. For doing so, we elaborated on a playful interaction de-sign framework and developed, based on it, an experimental mixed reality (MR) application that deployed multi-modal and playful user interaction experiences. A user evaluation woth 30 participants revealed that introducing playful characteristics in the design of MR graphical passwords had a catalyst effect on the security of user generated passwords and simultaneously affected significantly end-users' perceptions and understanding related to security semantics of graphical passwords.


Assistant Professor (2021-) at the Department of Electrical and Computer Engineering, University of Patras

Assistant Professor (2016-2020), Tenure-track Lecturer (2013-2016) at the Department of Cultural Heritage and New Technologies, University of Patras

  • New Interactive Media (M.Sc.)
  • Human-Computer Interaction (B.Sc.)
  • Structural Programming (B.Sc.)
  • Visual Programming (B.Sc.)
  • Pervasive Computing and Cultural Heritage (B.Sc.)

Visiting Assistant Professor at the Department of Computer Science, University of Cyprus (2011-2013)

  • Human-Computer Interaction (B.Sc.)
  • Programming Priniciples for Engineers (B.Sc.)
  • Operating Systems (B.Sc.)
  • Introduction to Computer Science (B.Sc.)

Adjunct Lecturer at the University of Patras, University of Ioannina, Technical Institute of Patras (2004-2011)

Academic Service


Prospective Students

I am always happy to discuss with prospective students new research endeavors in the areas of Information Systems and Culture, Modelling Human Cognition in Interactive Systems, and Usable Security. If you are interested to discuss your research idea please don't hesitate to contact me at fidas AT upatras.gr

Suggested Topics for Ph.D.
  • AR and VR Effects on Human Cognition within Cultural Heritage Informatics
  • Investigating the Effects of Human Emotions in User Authentication
  • Adaptable User Authentication in Ubiquitous Computation Realms
Ph.D. Students (supervised)
  • Kyriaki Konstantina: Eye Gaze and Electroencephalography Driven Framework for Human Memory Modeling - March 2021-
Ph.D. Students (co-supervised)
  • Argyris Constantinides (with University of Cyprus): Leveraging on Users' Cultural Factors for Increasing Graphical Password Memorability and Security - Jan. 2018-
  • Christina Katsini: Methods and Techniques for Usable and Secure User Authentication in Natural User Interaction - Sept. 2016-
  • George Raptis: A Personalized Cultural Heritage Framework based on Human Cognitive Processing - Successfully defended July 2020
  • Marios Belk: Adaptive Usable Security: Personalising User Authentication and CAPTCHA based on Individual Differences in Cognitive Processing - Successfully defended December 2015
M.Sc. Students (supervised)
  • Despoina Strataki: The Virtual Museum and its Didactic Use in Primary Education - 2020
  • Artemis Diamanti: Smart Cities and Culture: Current and Future Trends Prospects - 2018

Scientific Community Service

Review Service in International Journals and Conferences

  • ACM Transactions on the Web
  • ΙEEE Transactions on Games
  • ΙΕΕΕ Transactions on Fuzzy Systems
  • IEEE Internet Computing Magazine
  • Behaviour & Information Technology, Elsevier
  • Journal of Network and Computer Applications, Elsevier
  • Computers & Security , Elsevier
  • Energy Research & Social Science, Elsevier
  • International Journal of Human - Computer Studies, Elsevier
  • Information Technology & People, Emerald
  • Computers and Education, Elsevier
  • Interacting with Computers, Oxford
  • IBM Journal of Research and Development
  • ACM CHI - SIGCHI Conference on Human Factors in Computing Systems