About Me

Basic Information

Handle Name

こおしいず or kcz or Cookies ¹

PGP Fingerprint

598C8E59DE9C21FFEB434A3E 80B59E49 D6D9B0FD [Keybase]

Education

Graduated from Dept. of Information Science, School of Science, Univ. of Tokyo

From

Niigata, Japan

License :

• Class 1 Driver’s License in Japan
• EIKEN 2nd Grade
• SuKen Pre-2nd Grade
• KanKen Grade 3
• Applied Information Technology Engineer Examination

SNS Accounts

Please visit links.

Activities

• Google CTF 2024: Got 2nd place in Quals as a team kijitora.
• DEF CON CTF 32: Got 11th in Quals as a team undef1ned.
• DEF CON CTF 31: Got 11th in Quals as a team undef1ned.
• DEF CON CTF 30 Final: Got 11th as a team ./V /home/r/.bin/tw though I didn’t join Quals at all. Thank you members!
• ISUCON book review: reviewed a part of a Japanese book about web service performance tuning from ISUCON contest perspective. Title: 達人が教えるWebパフォーマンスチューニング 〜ISUCONから学ぶ高速化の実践, ISBN: 978-4-297-12846-3 [技術評論社 (publisher)], [Amazon.co.jp]
• CTF book review: reviewed the Web genre part of a Japanese book about CTF. Title: 詳解セキュリティコンテスト CTFで学ぶ脆弱性攻略の技術, ISBN: 978-4-8399-7349-0 [マイナビ出版 (publisher)], [Amazon.co.jp]
• TSG CTF 2021: hosted a 24hr CTF with TSG members. [ctftime]
• ISUCON11: passed Quals and got 3rd in Final as a team FetchDecodeExecWrite.
• Google CTF 2020: 18th in Quals and 2nd in Finals as a team I Use Bing (a joint team made of several Korean and Japanese independent teams). [video]
• LINE CTF 2021: 7th as a team TSG.
• ISUCON10: passed Quals and got 6th in Final as a team FetchDecodeExecWrite.
• TokyoWesterns CTF 6th 2020: 9th as a team TSG.
• TSG CTF 2020: hosted a 24hr CTF with TSG members. authored 1 challenge. [ctftime]
• CTFZone 2020: 7th in Finals after 10th in Quals as a team TSG.
• ISUCON9: participated in Quals and Final as a team FetchDecodeExecWrite.
• TSG CTF: hosted a 24hr CTF with TSG members. authored 3 challenges. [ctftime]
• ISUCON8: 2nd in Quals and competed in Final a team FetchDecodeExecWrite(moratorium, akouryy and me) [my blog]
• CODE BLUE CTF 2018: 4th in Quals as a team TSG(many members)
• CODE FESTIVAL 2015: 122nd in Qual A and competed in onsite event CODE FESTIVAL 2015.
• ACM ICPC 2015: 12th in Domestic Quals as a team tekito(satos, kivantium and me), but I did nothing but printing.
• Security Camp 2013 in Tokyo: tutor in Software Security class
• SECCON CTF 2012: 1st place in Quals at Yokohama and 2nd place in Final as a team wasamusume(mimura, carme, dec, atgw, ytn and me) [blog]
• Security Camp 2012 in Tokyo: student of Software Security class (in CTF, won 1st prize as a team | (4 members including me) and MVP as an individual)