Network Security #
From the point of view of finding a job, cyber security, although you can find good working conditions and good pay, also because of the sensitivity of the industry, resulting in the actual choice is limited, after graduating from a foreign school, you may only be able to choose companies and other units.
Therefore, although it is not recommended as a preferred major, it is perfectly acceptable to consider if you like the profession.
Capture the Flag (CTF) #
The CTF Wiki also provides good introductory and advanced content.