ZeroDays CTF 2023: Largest One-Day Cybersecurity CTF in the World takes place in Dublin

by Mark Lane, ZeroDays CTF

ZeroDays Capture-The-Flag (CTF) is an annual event aimed at promoting cyber-security as an exciting career and college choice. The event has been running since 2015 and has grown year on year. The 2023 event, held on Saturday 1st April at Croke Park, was the largest one-day, on-site CTF in the world, with 140 teams of four and over 500 participants.

The event is divided into three sections, one for Secondary Schools, one for Irish Colleges, and an Open Section for graduates, industry professionals, and anyone else interested in cyber-security. The focus is on fun and inclusiveness with this year’s theme “Lord of the Rings v Harry Potter.” The challenge caters for all levels, from noobs to elite hackers, with challenges ranging from lock-picking and trivia to web hacking, cryptography, forensics, and many more.

ZeroDays CTF Winners 2023


school winners


Open Industry

Industry (2nd Place)

ZeroDays CTF Industry Winners

It was the second year with a CTF for Secondary Schools, and the interest from students has been remarkable with a threefold increase from 2022. The growth of the Schools and the Colleges section of the CTF has led to the discovery of new talents for the Irish Cyber Security Team, which takes part in ENISA’s annual European Cyber Security Challenge being held in Norway in October this year. 

As a training ground to find new and young cyber talents, ZeroDays CTF has attracted support from industry, academia and government, with many sponsors present on the day. International companies such as ReliaQuest, Amazon, CrowdSec, State Street, Bank of America, and Elastic were joined by Irish companies and organisations such as Edgescan, EKCO, Cyber Ireland, BH Consulting, CommSec, TU Dublin, Science Foundation Ireland and Cyber Skills.

The event was attended by Minister for Cybersecurity Ossian Smyth and Senator Gerard Craughwell, who heads up a high-level think tank on the future of cyber-security in Ireland.

Over 50% of participants attending their first CTF event, and a post-event survey revealed that over 95% of participants would participate in further CTFs based on their positive experience at ZeroDays.

Looking forward, the event will continue to grow, with the possibility of regional events or a national league a real prospect. The event was made possible by the hard work of the organisers, sponsors, and participants who created an electric atmosphere on the day. 

ZeroDays Capture-The-Flag is a unique initiative highlighting the importance of cyber-security and supporting the development of the next generation of cyber security professionals in Ireland.

ZeroDays CTF 2023 Video