The course will be offered as an 2-credit course in the Spring semester. Students who have passed COMP4901N and have gotten the instructor consent can join COMP4901O in a subsequent Spring semester, they will be working together based on the knowledge they have learned from COMP4901O, forming teams to further investigate various advanced topics related to the more practical side of cybersecurity. They will then join the various cybersecurity contests. The students will get 2 credits for successfully completing COMP4901O. Contest-type “attack and defend” programming problems (also known as Capture-The-Flag, CTF, problems) will be employed throughout this course to practically train the students for the cybersecurity contests. The topics covered will include but not limited to binary analysis, cryptography, web exploitations, and packet capture analysis. These topics will be covered in the practical attack-and-defend context. Recent developments in the topics will also be investigated by students via CTF problem solving. Instructor's approval is required.