A CTF team from Network Security Lab of National Taiwan University

About Members Awards Contact Writeups CTFtime Twitter


Thanks for all the teams participating in Balsn CTF 2021. We hope you enjoyed our challenges. If you like our CTF, please help vote weight in CTFTime or provide feedbacks. We really appreciate your support and feedback!

Congratulations to the following teams:


Balsn is CTF team from Taiwan founded in 2016. Most of our current members are affiliated with Network Security Lab in National Taiwan University. We actively participate in online and onsite CTF competitions. You can browse our recently participated events and rankings on CTFtime. We also publish writeups on CTF challenges.

We are a group of cybersecurity enthusiasts interested in various areas including software security, binary analysis, web security, cryptography, IoT security, and etc. Besides our own research, all of us enjoy playing CTF because we believe it is an excellent chance to hone our skills in practice, catch up with the latest trend, and most importantly – compete and have fun!

In 2020 summer, Balsn attended DEFCON 28 CTF World Final online as a joint team HITCON⚔Balsn, collaborating with HITCON. We ranked in third place in this great competition.

Team Members

Active Members

Current leader of Balsn. (๑•ᴗ•)⊃━*✩⁺˚🕸
Pwning my life. (๑•̀ㅂ•́)ﻭ✧
Github: yuawn
Twitter: _yuawn
Give me flag (・ω・)
Yet another Shaman King of Balsn. He focuses on all kinds of challenges.
I enjoy playing web challenges!
- Blog: https://bookgin.tw
- Twitter: @bookgin_tw
sces60107 (a.k.a Shaman King) knows nothing about reverse engineering and binary exploit, but he knows how to get the flag. This guy specializes in mind-reading and guessing the flag.
Warning: He is a dangerous guy. Everything he touched will malfunction in a jiffy.
Blog: https://x9453.github.io/
I love CTFs, but they don’t like me…
mainly studied in pwn and crypto
Nothing to do with RB Tree
Blog: https://blog.rb363.tw/
struggling with solidity QQ
∠( ᐛ 」∠)_
Website: kaibro.tw
Blog: blog.kaibro.tw
Nothing … Something … Anything … Everything
blog: blog.terrynini.tw
Frank Lin
I’m a huge fan of sasdf!
github: Frank Lin
Play crypto but am learning pwn OwO
ε≡ヘ( ´∀`)ノ Crypto
A newbie who knows a little RE (a.k.a. Reverse Elephant).
I love misc!
pwn newbie who is finding crystal ball.

Honorary Members

> “This might be a game, but it isn’t something you play.”
Blog: https://poning.me
Transfer from pwn to web. Often got a production boost at the last hour of a game.
Blog: https://ysc21.github.io
Solve the challenges ranging from pwn to crypto, from crypto to bruteforce, from butefore to guessing, from guessing to ESP…
is my waifu.
( The challenge I can solve ) ≡ ( The challenge which is too easy )
> “Every challenge is brute-forceable if you believe in yourself.”
For me, 500 500 CAPTCHAs are just an hour of human work.
Welcome to the world of CTF.
A girl studies in computer science and interested in classical music.
She has absolute pitch and used the ability to decode music in D-CTF final. She is now focusing on the area of machine learning.
Blog: 0x00.tw
Twitter: @0x000050
A student who interested in binary analysis and like to PWN everything.
BalsnCTF System Guardian. (OwO)^
Lead System Architect of BalsnCTF (2019, 2020)

Selected Awards

DEFCON 28 CTF Finals, 3rd place (HITCON⚔Balsn) Online, Aug. 2020
DEFCON 27 CTF Finals, 2nd place (HITCON⚔BFKinesiS) Las Vegas, USA, Aug. 2019
DEFCON 26 CTF Finals, 12th place (BFS) Las Vegas, USA, Aug. 2018
HITCON CTF 2021, 2nd place Online, Dec. 2021
Dragon CTF 2021, 1st place Online, Nov. 2021
0CTF/TCTF 2021 Finals, 3rd place Online, Sep. 2021
PlaidCTF 2021, 4th place Online, Apr. 2021
WCTF 2020, 1st place Online, Nov. 2020
0CTF/TCTF 2020 Finals, 2nd place Online, Sep. 2020
Codegate CTF 2020 Finals, 3rd place Online, Sep. 2020
0CTF/TCTF 2019 Finals, 2nd place Shanghai, China, Jun. 2019
HITCON CTF 2018, 3rd place (BFKinesiS) Online, Oct. 2018
Trend Micro CTF 2019 Finals, 3rd place Tokyo, Japan, Nov. 2019
Pwn2Win CTF 2019, 2nd place Online, Nov. 2019
TokyoWesterns CTF 5th 2019, 1st place Online, Sep. 2019
Facebook CTF 2019, 2nd place Online, Jun. 2019
PlaidCTF 2019, 4th place Online, Apr. 2019
Teaser Dragon CTF 2019, 3rd place Online, Sep. 2019
N1CTF 2019, 2nd place Online, Sep. 2019
RCTF 2019, 3rd place Online, May. 2019
*CTF 2019, 3rd place Online, Apr. 2019
Teaser CONFidence CTF 2019, 2nd place Online, Mar. 2019
Codegate CTF 2019 Final, 6th place Seoul, Korea, Mar. 2019
HITB-XCTF GSEC CTF 2018 Finals, 5th place Singapore City, Singapore, Sep. 2018
Pwn2Win CTF 2018, 1st place Online, Nov. 2018
Hackover CTF 2018, 2nd place Online, Oct. 2018
ASIS CTF Finals 2018, 5th place Online, Nov. 2018
DefCamp CTF Finals Bucharest, Romania, Nov. 2018
DefCamp CTF Finals Bucharest, Romania, Nov. 2017
Trend Micro CTF 2018 Finals Tokyo, Japan, Dec. 2018
SECCON 2018 Finals Tokyo, Japan, Dec. 2018
SECCON 2017 Finals (1$@AIS3, Balsn) Tokyo, Japan, Feb. 2018


Please contact us at balsn2015 [at] gmail [dot] com. You can write the mail in Chinese, English or Taiwanese.

If you have any question regarding our writeups, please feel free to create an issue in the writeup repository.

This website is hosted on GitHub Pages. Please refer to GitHub’s privacy statement for more information.