WHAT IS A CTF?

CTF stands for "Capture the Flag," which is a common format for security competitions. Pieces of information called "flags" are put inside of servers, images, websites, or otherwise hidden so that they are difficult to access. Flags often take the format of "flag{this_is_a_flag}," but not always. Flags can be acquired by hacking a website, reverse engineering a piece of code, decrypting a message, or a variety of other means. The goal of the competition is to find flags. Competitors can then submit flags to earn points.

PicoCTF is a good starting point for learning competitive ethical hacking. PicoCTF is the largest annual CTF competition for middle and high schoolers, hosted by Carnegie Mellon University, but registration and problem sets from previous years are open year round.