Zero Day Arena
They fought with swords.
Now they fight with laptops.
Backed by COPG Global
CTF infrastructure — hosted
Backed by COPG Global
Run Jeopardy and Attack-Defense events on infrastructure that holds. Scoreboard tested. Anti-cheat on Pro Event and Enterprise. No servers to manage.
Jeopardy for puzzle-based scoring. Attack-Defense for live service exploitation. Same platform, same guarantees.
KNOWN FAILURE MODES
| Incident | Seen at | Our response |
|---|---|---|
| Scoreboard stalls when every team refreshes at once | Event start, final hour | Cached snapshot + push-invalidate. Load-tested at 500 teams |
| Flag sharing found only after the event | GPN CTF 2025 · 53 incidents ↗ | Per-team flags, checked against every team on each submission, during the event |
| Infrastructure built the night before | Self-hosted events | Hosted platform. No cluster, VPN or load balancer to run |
Why it holds
Anti-cheat by default
T8801 submits FLAG{c18e55b07a93f4d1}
FLAGGED · belongs to T2039 · caught on submit
evidence bundle → 2-organizer review queue
Flags are derived per team with an HMAC, so a shared flag names its source the moment it's submitted. No CSV exports after the event, no guesswork.
Scoreboard under load
teams updated
0/500
elapsed
0.0s
Illustration of one update reaching every team. Measured in load tests: p95 < 5s at 500 concurrent teams.
A score change pushes an invalidation; clients pull a cached snapshot from Redis instead of hitting the database. Load-tested at 500 concurrent teams, updates under 5 seconds at p95.
Zero infrastructure
What a self-hosted CTF needs
Your part: the challenges.
No cluster, no load balancer, no VPN to wire up the night before. The platform is hosted and monitored through your event.
Every point explainable
rebuilt total
0
Score events are append-only — even a penalty is a new event, never an edit. Any total on the board can be replayed for a dispute, an audit, or a CTFtime export.
What the platform does today, stated plainly. If a line here changes, this page changes with it.
| Metric | Definition | Value |
|---|---|---|
| Flag submit latency | Time from a flag submission to its correct / incorrect response, 95th percentile. | < 150 ms |
| Scoreboard update | Time from a solve to that solve appearing on every connected scoreboard, 95th percentile, 500 concurrent teams. | < 5 s |
| Answered submissions | Share of flag submissions that receive a correct / incorrect response. A silent failure counts against it. | 100% |
| Attack-Defense tick | Interval between flag rotations and checker rounds. Configurable per event. | 30 s |
Measured in our own load tests. Ask for the setup and raw results on your demo call.
Name it, set the dates, choose Jeopardy or Attack-Defense. Pick a plan.
Upload challenges, set point values, enable containers. Import from a previous event or a platform template.
Players get their link. Flags, scoring, anti-cheat, and the scoreboard run without you touching them.
Founding organizers · 2027 events
Zero Day Arena is onboarding its first organizers now. We'd rather show you the platform than quote people you've never heard of.
Your demo, your setup review and your event-day support come from the engineers who built the platform.
We walk through your event with you before players arrive: challenges, scoring, containers, limits.
Requests from founding organizers go straight into the roadmap discussion, with a reply either way.
Pricing and plan questions are on the pricing page.
Zero Day Arena is a hosted platform for running Capture The Flag (CTF) security competitions. It supports both Jeopardy and Attack-Defense formats: the organizer configures the event, and Zero Day Arena runs the infrastructure, scoring and anti-cheat.
It is built for people who organize CTFs: university CTF clubs and security courses, security conferences, corporate red teams running training or hiring CTFs, and public CTF organizers.
Every team gets its own flag for every challenge, derived with an HMAC from a server-side key. Each submission is checked against all teams' flags, so a shared flag is identified, along with the team it came from, the moment it is submitted. Penalties require evidence and confirmation by two organizers.
Yes. Zero Day Arena runs the full Attack-Defense game plane: a WireGuard VPN per team, vulnerable services per team, sandboxed automated checkers, and HMAC flags per team, per service and per tick, with ticks of 30 seconds by default.
The scoreboard is load-tested at 500 concurrent teams, with updates reaching every scoreboard in under 5 seconds at the 95th percentile. Flag submissions get a response in under 150 milliseconds at the 95th percentile.
CTFd is an open-source platform you can self-host or buy hosted, with a large plugin ecosystem, and it focuses on Jeopardy. Zero Day Arena is hosted-only, supports Attack-Defense natively, and uses per-team flags for every challenge by default. It has no plugin system.
Plans are priced per event. Community is ₹4,999 for up to 50 teams. Pro Event is ₹9,999 plus a per-challenge cost, for up to 500 teams, with dynamic containers and anti-cheat signals. Enterprise is custom, with dedicated infrastructure.
Zero Day Arena is an independent CTF platform with its own team and roadmap. Its parent company is COPG Global.
₹4,999 / event · up to 50 teams
Book a demo →₹9,999 / event + per challenge · up to 500 teams
Book a demo →Custom pricing · dedicated infrastructure
Talk to us →Overages are soft: we warn you at 80%. We never cut off a live event. Full plan comparison →
We walk through a live platform, answer every question about your specific event, and tell you exactly what plan fits. No sales deck.
Book a demoResponse within 24 hours. We review every request.