Ctf means CaptureTheFlag. CTF(CaptureTheFlag) is a network security competition. Its purpose is to let the contestants crack the target system, decrypt the data and get the logo, thus improving the technical level of network security personnel. CTF competitions are divided into different categories, such as hackers, web pages and reverse categories, and each category has different difficulty levels and rules. CTF is a popular form of information security competition. Its English name can be literally translated as "Winning Flag" or literally translated as "Winning Flag Competition". The general process is that the participating teams take the lead in obtaining a string of characters or other contents with a certain format from the competition environment given by the organizer through the forms of offensive and defensive confrontation and program analysis, and submit them to the organizer to win points. For convenience, such content is called "logo".