LINE CTF 2023 Online Competition to Put Teams' Security Skills to the Test

2023.03.06 Technology

● Event looks to build momentum and drive further progress in the security community


TOKYO – March 1, 2023 – LINE Corporation ("LINE") will be hosting LINE CTF 2023, an online competition that pits teams against each other in a contest of security skills and knowledge.

In capture the flag (CTF) events, competing teams utilize cybersecurity techniques and their IT skills and knowledge to solve technical puzzles and score points. LINE has held the LINE CTF event each year since 2021, aiming to rouse more interest in cybersecurity and continue with efforts to grow the community. The first LINE CTF event in 2021 welcomed 680 teams and over 1,200 participants from around the world, including students, engineers, and other security enthusiasts. In 2022, there were 1,857 participants spanning 1,061 teams.


LINE CTF 2023 will have a diverse lineup of puzzle categories such as "Pwnable" (program vulnerabilities), "Web" (web applications), "Crypto" (encryption), and "Reversing" (binary analysis).


LINE CTF 2023 official website:




LINE has adopted a wide range of measures to strengthen the security of its services and build up a store of knowledge. In one initiative, a dedicated security team engages in all stages of a service's development life cycle—from planning and design, to implementation and release—providing support and testing to eliminate any design flaws and implementation vulnerabilities.

LINE also maintains service reliability by using internally developed data analysis systems to detect and deter account takeovers, spam, and other misuse, as well as having the internal security team and third parties conduct regular penetration tests to protect the LINE app's security.

Launched in 2016, the LINE Security Bug Bounty Program ( is yet another part of efforts to actively gather knowledge from both internal and external sources. This public program rewards those who detect and report vulnerabilities (or "bugs") in the LINE messaging app and other LINE services.


Through a diverse range of initiatives, LINE will continue its efforts to generate momentum in the tech community and support further growth.



About LINE CTF 2023

・When: 9 am on March 25 – 9 am on March 26, 2023 (JST)

・CTF style: Jeopardy-style (online team competition) 

・Prizes: Total of USD 10,000 (1st: USD 5,000 / 2nd: USD 3,000 / 3rd: USD 2,000)

・How to enter: Pre-register your team at



Updates on the event will be added to these channels.

・ LINE CTF 2023 official website:

・ CTF Time:

・ Discord:


・ Twitter: (JA) / (EN)