Signups for Qualifiers are now open HERE!

$ ctf -h

Grey Cat The Flag is an annual CTF hosted jointly by NUS Greyhats and Division Zero (Div0), supported by the National Cybersecurity R&D Lab.

Division Zero (Div0)
NUS Greyhats

Remember to stay tuned to our socials and join the GreyCTF Discord to stay updated!

What is CTF?

CTF (Capture The Flag) is a kind of information security competition that challenges you to solve a variety of tasks ranging from a scavenger hunt on wikipedia to basic programming exercises, to hacking your way into a server to steal data. In these challenges, the contestant is usually asked to find a specific piece of text that may be hidden on the server or behind a webpage. This goal is called the flag, hence the name!

If you are new, don’t worry! We will be sharing resources in our Discord server every now and then.

Learn more about CTFs

$ stat ctf

There will be two categories this year

  1. Local Category consists of: NSFs, students that are currently enrolled in an educational institute in Singapore (team should consist of at least one Singapore Citizen), singapore citizens studying in an overseas institution

  2. Open Category consists of: all participants who do not qualify for the local category, participants who are eligible for the local category but opts in for the open category

There will be an onsite finals for the top 20 teams in the local category. Each team may send up to 4 people for the onsite finals.

Regrettably, we are unable to accommodate international teams for the onsite finals this year.

On the bright side, we will have attractive cash prizes up for grabs the top 3 teams in our Grey Cat The Flag Qualifiers.

$ stat summit

We are excited to announce that we are hosting our very own Summit this year in Singapore!

This event will include talks and workshops on cybersecurity, with plenty of chances to meet new people during breaks and over lunch and tea.

Plus, you will have the opportunity to hear from our sponsors as well as concluding with the CTF prize presentation.

We hope that you will join us for this fantastic summit!

More details coming soon

$ where ctf

datesevents
31st May, 8pm to
1st June, 8pm
Qualifiers, Online
28th June, 10am to
29th June, 10am
Finals @ NUS COM1
5th July, 9am to
5th July, 5.30pm
GCTF Summit @ NUS COM1

(all timing are in GMT+8 timezone)

$ man prize

open category

rankingprize
1st placeSGD 2000
2nd placeSGD 1000
3rd placeSGD 500

local category

rankingprize
1st placeSGD 6000
2nd placeSGD 4000
3rd placeSGD 2500
4th placeSGD 1500
5th placeSGD 1000
6th-10th placeSGD 500
special prizesstay tuned!

$ whois sponsors

We would like to extend our heartfelt gratitude to our sponsors .

Infra sponsored by goo.gle/ctfsponsorship

$ FAQ

Join our Discord server if you have more questions.

Q: Is there a team size limit for qualifiers?

A: There is no team size limit for qualifiers. You can have as many team members as you want. However, please note that each team can only send up to 4 members for the finals.

Q: What categories are there?

A: Web, Pwn, Crypto, RE, Blockchain, Forensics, Misc

Q: Is this CTF beginner friendly?

A: Yes! But we also have hard challenges for the stronger teams.

Q: What's the flag format?

A: grey{...}

$ history

Past Winners

2024

rankingprize
1st placeslight_smile
2nd placensmallows
3rd place

2023

rankingteam
1st placer3kapig
2nd placeDiceGang
3rd placeSocial Engineering Experts

2022

rankingteam
1st placecatssg
2nd placenushmellows
3rd placeStranglehold