"CAPTURE THE FUTURE." image by @polamjag

tkbctf4 is over

tkbctf4 has finished!

Here are the final TOP 10.


Rank Name Point
1st 0x0 2541
2nd MMA 1987
3rd dcua 1870
4th superflip 1655
5th HackingForSushi 1461
6th nonbei 1200
7th tuat_mcc 1200
8th 竹田氏 1113
9th encrypti0x0n 806
10th CureSecure 800

Thank you for your interest in tkbctf4. We all enjoyed it. We hope you did, too.

Bye for now! Oh, and don’t forget to publish writeups!

tkbctf4 Schedule Announcement

Yo! It’s Chris here.

I bet many of you have been wondering WHEN exactly tkbctf4 will take place. Here’s an official announcement!

Online match

Starts at Suspends at
2014-11-02T03:00:00+0000 2014-11-02T15:00:00+0000
Resumes at Ends at
2014-11-03T01:00:00+0000 2014-11-03T10:00:00+0000

On-site match at Tsukuba University (Simultaneous with the 2nd half of the online match)

OH NO! On-site match has been cancelled due to lack of participants.

We’re very sorry about it. However, online match will be carried out as scheduled.

Thank you for your interest in tkbctf4. Happy Pwnage!

tkbctf4 registration will begin!

Good morning from Japan! This is Christopher, a member of tkbctf4 team.

We are very excited to tell that we are pretty much ready to accept user/team registrations!
User/Team registrations will open in less than 6 hours from now.

For more information, please visit tkbctf4’s scoreboard server.

Thank you for your patience. It’s coming up.

P.S. We have previously stated that the second day of tkbctf4 (that is Nov 3) will be held at Tsukuba University, JAPAN.
Well, guess what. It will be held as one of the attractions of our University’s campus festival!
So you can hack and slack. Cool!

Announcing tkbctf4

tkbctf4 logo

Hello from tkbctf4 team!

Let us announce that we are going to hold tkbctf4 on the 2nd and 3rd of November.
On the first day will be an online CTF game, and on the second day the game (and some bonus games!) will be held at a CTF arena in Tsukuba, Ibaraki, JAPAN.
For those who won’t be able to visit Tsukuba on that day: Don’t worry. The online game will also be held on the 3rd.

We are anxious about your participation.

That’s all for now. Please stay tuned!

tkbctf3 is over!

tkbctf3 is over! Thanks you for all players.

Here is the final ranking.

1st: dcua, 2nd: _MMA_, 3rd: superflip.
Congraturation dcua!!!

Operation room 1 Operation room 2

We are looking forward to read your write-up.
Have a nice week.

This post was delayed due to technical trouble. Sorry for the delay.

Registration is now open!

Registration for tkbctf3 is now open!

  • (for team leaders) Team Registration
  • (for players) Sign up
    All players must be belonged to a team. (You can make a team with one person.)

If you find a bug on the registration system, create an issue or contact the developer on twitter.

Team registration ends at 2014/05/04 12:00 JST. tkbctf3 starts at 2014/05/04 12:00 JST and ends at 2014/05/05 06:00 JST.

tkbctf3 will be jeopardy style. We will make further announcement here.

Old Posts Migrated

The old posts has been migrated into the new site.


We changed the structure of permalinks. The new permalink and the old one are completely incompatible.

The old style permalinks (e.g. /archives/281) is still available only for the old posts. If you access with the old style permalink, you will be redirected. Please use new style permalinks (e.g. /blog/2014/04/website-renewal/) in future.


tkbctf3 logo