Our Core Team

Christos Xenakis


Prof. Christos Xenakis is a faculty member of the Department of Digital Systems of the University of Piraeus, Greece, and a member of the Systems Security Laboratory. He is also a steering committee member of the European Cyber Security Challenge (ECSC) and the leader of the Hellenic Cyber Security Team. He is a member of the editorial board of four Thomson Reuters indexed journals: a) Computers & Security Journal of the Elsevier publishing, b) Computer Communications Journal of the Elsevier publishing, c) IET Information Security of the Institute of Engineering and Technology and d) The Computer Journal of the Oxford University Press. His research interests are in the field of systems, networks and applications security. He has authored more than 100 papers in peer-reviewed journals and international conferences.

Stella Tsitsoula

Communications & Sponsorship manager

Stella Tsitsoula is a communications consultant specialised in the Tech and Cybersecurity industry who works with multi-national organisations and universities to help them understand emerging technologies, manage risk and strategise on a future roadmap to thrive in changing times. She also promotes the ECSC events and the national team of the Hellenic Republic. She has her own Communications agency. For more than 25 years she holds senior management positions with extensive experience in media and communications business. Stella Tsitsoula has a B.Sc degree in Electronic Computing Systems Engineering from the Piraeus University of Applied Sciences, a PGCert in Management of Public Relations of the University of Athens and currently enrolled in an MBA program and is Certified ISO 9001 Lead Auditor. She is a member of the Greek Periodical Press Association and International Federation of Journalists. Stella is also a Co-Founder of Women4Cyber Greece, where she leads the team for Communications.

Panagiotis Bellonias

Team Coach

Panagiotis Bellonias is a highly skilled cybersecurity professional with a passion for competitive hacking. As a member and ex-captain of the Hellenic Cyber Security team, he honed his skills in cryptography and has since gone on to achieve success in various competitions. He is a member of Zer0Tolerance, a top 50 CTF team globally, and has participated in various cybersecurity competitions, including the International Cyber Security Challenge where he achieved first place as a member of Team Europe. Panagiotis has a strong background in research, having worked as a researcher at Bournemouth University, where he developed his skills in network analysis, software development, and online investigations. Today, he is applying his expertise as a security specialist in the Netherlands, where he conducts security assessments for a wide range of clients in the industrial market.

Angelos Taxiarchis Kalaitzidis works as an information systems security researcher, his subject is finding and exploiting vulnerabilities in popular programs. He started to deal with the field by accident in his first student years. From then until today, he has not stopped being fascinated by the intricacies of software systems, particularly in how they interconnect and the potential for creative vulnerabilities that can arise from these connections. Being an active member of the community, he has founded and participated in numerous groups related to the field.

Michalis Takaronis

Technical manager

Michalis Takaronis is a research assistant in the SSL team at the University of Piraeus, specializing in vulnerability assessment and exploitation development. He actively participates in various university research projects, particularly those related to hosting and content creation for Capture the Flag competitions. In his free time, he participates in online CTF competitions, but also takes pleasure in crafting challenging scenarios across different fields of cybersecurity.

Athanasios Grammatopoulos

Scientific Manager

Athanasios Vasileios Grammatopoulos is a Cybersecurity Researcher. His research focuses on the fields of Cybersecurity Training, Vulnerabilities Detection and Secure Password-less Authentication. He received his second MSc from the Digital Systems Dept. of University of Piraeus on Digital Systems Security. He received his Electrical and Computer Engineering Diploma and MSc at the Technical University of Crete.

Aggeliki Gioti

Support Team

Associate Research Assistant in System Security Laboratory of the University of Piraeus. Aggeliki holds a Bachelor’s Degree in Computer Science and is pursuing a Master’s Degree in Digital Systems Security from the Department of Digital Systems in University of Piraeus. Specializing in cybersecurity and penetration testing she also actively participates in CTF competitions.