<p>Grey Cat The Flag (GreyCTF) is an annual jeopardy-style Capture The Flag cybersecurity competition organised by NUS Greyhats, with a dedicated Local Category for teams of Singapore Citizens and PRs. Challenges span AI, Crypto, Forensics, Pwn, Reverse Engineering, Web, and Misc categories, catering to beginners while still offering difficult problems for experienced teams.</p> <ul> <li>Participants must be undergraduate or pre-university students (e.g. NSFs, JC, Poly or ITE students); the International Category also admits Master's students</li> <li>Local Category: teams made up entirely of Singapore Citizens or PRs; all other teams compete in the International Category</li> <li>Qualifiers held online with no team size limit; up to four members per team for the in-person finals</li> <li>Structure: online qualifiers (30–31 May 2026), in-person finals at NUS COM1 (27–28 June 2026), and a summit on 4 July 2026 featuring talks, workshops, and networking</li> <li>Participants under 18 require parental consent</li> </ul> <p>Registration is free.</p>