SINF 2020 CTF Rules

SINF 2020 CTF will take place from November 6th to November 11th, 2020. The first challenges will become available on the 6th at 21h30 WET, and the contest closes on the 11th at 16h00 WET.


Participants can compete in teams of up to 4 people. Every participant is required to be registered in the conference to be eligible for prizes. Please use the same email address when performing both registrations. They are also required to be university students. If they place Top 3, participants will need to provide proof of their enrollment at their higher education institution.

Challenge Typology and Scoring

The contest consists of a series of challenges in the typical Jeopardy format. They will be in the following categories: Web, Cryptography, Forensics, Pwn, Reverse, Trivia and Miscellaneous.

The first challenges will be published at the start of the competition, and more challenges will continue to be released over time until the contest ends.

The scoring system is dynamic scoring (the number of points that a challenge is worth is inversely proportional to the number of teams that solved it).

For example: A challenge's initial value is 500 points. If team A solves it, their score is 500 points. If team B solves it afterwards, they get 450 points and team A's score is also updated to 450 points. If other teams solve it, the score drops further (values given only as an example).

As such, harder challenges (with less solves) are worth more than challenges with more solves. There is no bonus for first solves (besides cool points 😎).

Teams will be ranked according to their scores (total points in all solved challenges) and ties will be resolved by the first team to reach that score (done via the platform's scoreboard automatically).


To the teams that place 1st, 2nd and 3rd, the following prizes will be awarded.

Further information

The flag format is SINFCTF2020{flag} in which flag is some human-readable text.

There are not many extra rules for the contest, but the following rules should be followed attentively:

During the contest, you can access the contest's Discord server at for support (i.e. did something break, is this supposed to be like this - no asking for hints!).

Please ping @meiogordo if a challenge is down, broken, has an unintended solution or is exploitable in some way.