Deadline: 18.03.2020

The goal of the capture the flag (CTF) is to solve some simple problems related to the material you've studied so far. The challenges range from finding hidden messages, to encrypting and decrypting messages, and analyzing webpages and executables.

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The project has only 1 part.

How to get started

This material contains capture-the-flag of the course series called Cyber Security Base. In order to submit your project, you will need a MOOC.fi account that you can create at at the right hand corner of this course material.

Once you have created the account, please answer a background questionnaire at https://elomake.helsinki.fi/lomakkeet/74256/lomake.html. Answering the questionnaire should take less than 10 minutes and will be very valuable for the research conducted on this course.

How to pass the course

The challenges in this CTF come in three difficulty levels: easy, medium and hard.

In order to ensure everyone has a fair chance to get the first completion, we're releasing the challenges in batches — easy challenges are to be released on Wednesday (11.3.2020), medium challenges on Thursday (12.3.2020), and hard challenges on Friday (13.3.2020).

The exercises are published starting from 15:00, and new exercise will be added roughly every 20 minutes.

There are 10 easy challenges, 9 medium, and 4 hard.

The exercises can be found here. Use your MOOC account to login.

To finish a challenge, find a special code and submit it to the site.

For certain challenges, binary inspection command line tools like strings or xxd will be useful.

To pass the CTF, you need to complete at least 80% the easy challenges and at least 60% of the medium challenges, before the deadline. The deadline for completing the challenges is 18.3.2020 (moved from the original deadline 16.3.2020)

This competition is individual work. Please do not share your solution or spoil the exercise, let's keep the competition fair and fun for everyone! :)

Some of the challenges expect you to analyze and/or execute a Linux 64-bit binary. If you have an incompatible OS consider setting up one in a VirtualBox.