2 Sandboxes 1  Past Challenge

More about the cyber security challenges

An international team of Replyers – all experts in cyber security – have devised a series of team-based online competitions. Join in, and you’ll have the opportunity to prove your skills while having fun and winning great prizes.


Capture the Flag edition on October 11th

The next Cyber Security Challenge will take place on 11th – 12th October 2019. Save the date! This will be the ‘Capture the Flag’ edition, where you have 24 hours to find 25 flags by solving 25 problems. REGISTER NOW, form your team of 1 to 4 members and get involved in the best secret mission ever. The fun starts on 11th October at 19.30 CEST.


Use past challenges to help you prepare

Past challenges are always available in sandbox mode – so you can practise by solving problems we’ve set before, and see how well you score. Plus, you can access the winning solutions, download them, and maybe learn from them.

Want more challenges?


Get ready for the next Cybersecurity challenge by training with the Past challenges and the sandbox problems.