05/04 07:00 - 05/05 07:00




  1. Don’t share flags or hints, or you’ll be banned.
  2. Don’t attack our score server, or you’ll be banned.
  3. Do not DoS, or you’ll be banned.
  4. The flag format is TSGCTF{blahblah}, unless otherwise specified.
  5. All challenges have dynamic score value, including sanity check.
  6. The prize reward is paid in Bitcoin with conversion according to the exchange rate on May 4, 2019.
  7. Writeups of solved problems are required to claim prizes. Plus, they will be open to the public.
  8. If you have any questions during the contest, please contact us via Discord server.


  • 1st: 513.31 USD
  • 2nd: 213.31 USD
  • 3rd: 113.31 USD


Flatt SECURITY is the cyber security assessment service provided by Flatt, Inc.

And Flatt is the company for cyber security based in Hongo, Tokyo, nearby The University of Tokyo.

Flatt is hiring engineers. Please contact to support@flatt.tech or to form in official web site.


TSG CTF is organized by TSG, the official computer society of The University of Tokyo.

Below is the full list of TSG members who contributed to this TSG CTF in success. So many thanks!!