Capture-the-Flag (CTF) competitions provide a nice way to test and enhance your skills in the field of information security and related areas. During a CTF problems are served from a number of categories, such as exploits, binaries, networking, forensics, web en crypto. For more information on CTFs, visit the CTF time website.
We sometimes design crypto challenges where the flag can be captured by breaking or bypassing a cryptographic mechanism. Often these challenges are based on real-life cryptographic weaknesses, sometimes these chalenges have been served on real CTF competitions. Note that in this latter case we may have provided one or more challenges but claim nor deserve any credits for the organisation and running of the CTF itself.
Below you find some of the challenges we have designed: