Capture The Flag

Photo Credit: Alexandre Dulaunoy

Capture The Flag

The 2017’s CTF will at again be held by FluxFingers, the CTF Team of Ruhr-Universität Bochum (Germany). This will be the seventh CTF held by the FluxFingers.

FluxFingers logo


Everyone may participate (onsite or offsite). If you want to be eligible for prizes, you need to have at least one member of the team onsite and you need to show up at the organizer’s registration desk at the conference before the end of the CTF so we can change your team status to local.


The CTF will take place during the conference and will last 48h hours like in the previous years.

  • Tue, Oct. 17, 10:00 — Thu, Oct. 19, 10:00 UTC




Registration now open! Fill your form here.


The CTF event will be ‘‘challenge based’’, i.e. the CTF is separated into small tasks that can be solved individually. The scoreboard will be web accessible and no VPN is required. We are trying our best to give all participants a delightful experience, the covered topics are somewhere around crypto, web security, reverse engineering and forensics. Have a look at the previous CTFs on the archive.

We are looking forward to seeing you participate - locally or from remote. Direct your questions to somebody at our booth or on IRC.


  • Each challenge gives base points (depending on difficulty) + first blood points (for the first three solves).
  • All normal challenges give 100 bonus points at the beginning. Bonus points can (and most probably will) decrease during the CTF, depending on the number of solves and how difficult we considered the challenge to be.
  • No DoS/automated scans/large amounts of traffic/deleting stuff on our servers.
  • If you find something that solves too easy it might be a bug. Please report it for possible bonus points.
  • Do not share flags or solutions with other teams. We will not tolerate flag sharing in the IRC channel.
  • If you break the rules we will kick your butt and remove all your points. Promised.


In order to balance points of misjudged challenges, we apply a bonus point algorithm this year. The bonus points will be calculated dynamically for each challenge, depending on how many teams solved it and how many solves were expected by our team. At the start of the CTF each normal challenge will have additional 100 bonus points, which will be decreased over time. The exact formula will be published when the CTF starts.

You will get your usual first blood points, too: First solve of a challenge yields 3 points, second 2 and third 1.

E.g.: A challenge gives you a total of “points = base + bonus + first blood”. Bonus points vary depending on how many teams solved the challenge. Note that this also counts for challenges that were already solved! The other points are fixed.