About

The ACSC is an open CTF (Capture The Flag) competition specifically for individuals under 26 in the Asian region. It also serves to select top players from member countries of the ACSC to form Team Asia, which will participate in the ICC (International Cybersecurity Challenge). The ACSC is not only an open competition but also aims to foster interaction and develop the skills of young people in Asia, providing an opportunity to nurture talented individuals who can compete on the global stage.

ACSC 2025

  • Date & Time
    • 12:00, Aug 16 — 12:00, Aug 17, 2025 (UTC+9)
  • CTF Style
    • Jeopardy-style (Individual Competition @ Online)

Rules / Prohibitions

Please read rules and prohibitions before registering as a user.

Rules

  • This is an individual competition. As noted in prohibitions, by no means players are allowed to communicate and cooperate with each other.
  • The flag format is ACSC{something}, unless otherwise specified.
  • Players need to submit a flag to the score server in order to get points.
  • The scoring system is dynamic. This means that the point value of each problem decreases as more participants successfully solve it. Also, there are no breakthrough (first blood) points awarded to the first solvers.
  • A player that has more points, ranks higher. If some players have the same points, the player that has made the last submission of a valid flag earlier, ranks higher among them.
  • For verification, the organizers may ask the top players to submit a brief writeup after the contest is over.
  • If there arise situations which are not covered by these rules, the organizers may make decisions on them as needed. The decisions made are absolute.

Prohibitions

If you break the following prohibitions, you will be disqualified and banned.

  • Players must not share flags or solutions with each other.
  • Players must not attack/obstruct other players.
  • Players must not attack the contest infrastructure other than the servers explicitly allowed to do so in problems. Also, players must not try brute-force attacks even to the allowed servers.

Finalist Selection

A player is eligible for selection to Team Asia if they meet the following conditions:

  • The player must hold the nationality of one of the ACSC Steering Committee member countries: India, Japan, Mongolia, Republic of Korea, and Taiwan.
  • The player is under 27 years of age. Born on or after January 1st, 1999. (The player must not turn 27 during the year the competition takes place.)
  • The steering committee will select 15 players (plus 2 substitutes) to form Team Asia.

<Finalist Selection Rules>

  1. Select the top 3 players based on overall score.
  2. Select the best player from each of the categories. If a player selected under Rule #1 is also the top player in any category, the next highest-ranked player in that category will be selected instead.
  3. Fill the remaining slots according to the overall score rankings.
  4. If a country has no players among the finalists, the highest-ranked player from that country will be selected as a substitute.
  5. If all finalists are of the same gender, the highest-ranked player of the opposite gender will be selected as a substitute.

Note: The selection process considers diversity across challenge categories, nationalities, and genders. These factors are considered naturally as part of the selection process, without giving them explicit priority.

Finalist selection may vary based on the budgetary constraints allocated per country.

If any selected player is unable to participate in the ICC for any reason, the next eligible player will be selected until 15 players (plus two substitutes) are confirmed to attend physically.

Organizers

Q&A

  • Can I participate and play ACSC, even if I am not eligible as a finalist?
    • Yes. You can participate and play ACSC even you are not eligible as a finalist. ACSC is an open CTF for anybody.
  • Do I need to pay for travel expenses to compete in ICC?
    • No. Travel and accommodation expenses for Asian final team members to participate in ICC will be provided by the supporting organization in each ACSC Steering Committee member country.

Privacy Policy

The ACSC Steering Committee will process your information as described in the Privacy Policy. By registering as a user, you agree to follow the rules of the ACSC CTF and our Privacy Policy.

Social Media

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Twitter - @acsc_asia