SURFcert hacking event Capture the Flag 2025
After the great success of previous editions, the SURFcert Capture the Flag (CTF) returns this year! And not just like that: we are celebrating the 10th edition with an exciting Jeopardy-style CTF. This year's theme is Computer History, a nod to the roots of the digital world. Do you dare to take on the challenge?
- SURF office in Utrecht
Challenging tasks combined with a touch of nostalgia
We challenge you and your team to the SURFcert CTF 2025! A day full of unique security challenges in which you will crack puzzles together, unravel codes and conquer flags. Expect a mix of challenging tasks, mysterious hints and a touch of nostalgia with old school bits and bytes.
Whether you are experienced or just feel like testing your skills: anyone can join (some prior knowledge is useful). So put your team together, sign up and enjoy a day full of excitement, fun and teamwork. Who knows, you might win! Do you dare to take up the challenge and write history?
What is a Capture the Flag (CTF)?
A Capture the Flag (CTF) is a competition in which participants, alone or in teams, solve puzzles and technical challenges. Roughly speaking, there are two types of CTFs: Jeopardy style and Attack & Defense style.
This event is a Jeopardy style CTF. That means your team will be given assignments within different categories, such as, for example, Web Hacking, Forensics, Cryptography, Decoding, Binary and more. The goal of each assignment is to find a hidden 'flag', often a specific string that is instantly recognisable. You enter that flag on the scoreboard. If the answer is correct, your team receives points. The more difficult the challenge, the more points can be earned.
The team with the highest score at the end of the game time runs away with the flag!
Programme
| 8:30 | Reception and registration |
| 9:15 | Welcome and introduction |
| 9:30 | Launch |
| 15:30 | End of CTF |
| 16:00 | Award ceremony |
| 16:15 | Q&A / drinks |
For whom?
Capture the Flag is intended for both staff and students of SURF member institutions and fellow CERTs.
Registration for Capture the Flag 2025
Be quick! Registration closes once the maximum of 125 participants has been reached, or no later than 10:00 on Monday 1 December 2025. Due to high interest in previous years, registration was often full well before the official closing date.
Have you registered and are unable to attend?
Cancel your (team) registration as soon as possible, so that teams on the reserve list can still participate.
Register as a team
- A team consists of a maximum of 4 participants, including the team captain. When registering, enter the team name in the comments field.
- The team captain indicates on the registration form that he or she is the team captain and also mentions the names of the team members.
- Please note that listing the team members only here does not give access to the CTF, that requires the individual registration.
- All participants register individually via the registration link and mention the team name, for example: ByteFighters2025
Register without a team
Don't have a team but still want to participate? Then register stating 'Single Player' in the team name field. SURFcert will then add you to another team.
Sign up now SURFcert hacking event Capture the Flag 2025
- SURF office in Utrecht