# Zero Day Arena

> Zero Day Arena is a hosted platform for running Capture The Flag (CTF) security competitions in Jeopardy and Attack-Defense formats. Organizers configure the event; Zero Day Arena runs the infrastructure, scoring and anti-cheat. It is an independent platform; its parent company is COPG Global (https://copgglobal.com).

## Key facts

- Formats: Jeopardy; Attack-Defense (30-second ticks by default, WireGuard VPN per team, sandboxed automated checkers, HMAC flags per team, per service, per tick).
- Anti-cheat: per-team HMAC flags for every challenge by default; each submission is checked against all teams' flags during the event; penalties require evidence and two organizers.
- Performance (own load tests, 95th percentile): flag submission response under 150 ms; scoreboard update under 5 s at 500 concurrent teams; 100% of submissions answered.
- Scoring: formula frozen before the event and published in the rules; append-only score ledger, exportable (CSV, CTFtime format).
- Plans: Community (₹4,999 / event · up to 50 teams); Pro Event (₹9,999 / event + per challenge · up to 500 teams); Enterprise (Custom pricing · dedicated infrastructure).
- Status: pre-launch, onboarding founding organizers for 2027 events.

## Pages

- [Home](https://zerodayarena.com/): overview, specification and FAQ
- [Jeopardy CTF](https://zerodayarena.com/jeopardy): how Jeopardy events and scoring work on the platform
- [Attack-Defense CTF](https://zerodayarena.com/attack-defense): the 30-second game loop and the infrastructure run for organizers
- [Pricing](https://zerodayarena.com/pricing): plans, limits and pricing FAQ
- [Book a demo](https://zerodayarena.com/demo): request a 30-minute demo
- [About](https://zerodayarena.com/about): principles, parent company and contacts
- [Platform specification](https://zerodayarena.com/#spec): capabilities, metric definitions and commitments

## Guides

- [How to Prevent Flag Sharing in CTF Competitions](https://zerodayarena.com/blog/ctf-flag-sharing): Flag sharing is the most common form of cheating in CTFs. Per-team flags and real-time detection are the only reliable solutions. Here's how they work.
- [CTFd Alternatives in 2026: An Honest Comparison](https://zerodayarena.com/blog/ctfd-alternatives): CTFd is the most popular self-hosted CTF platform. Here's how rCTF, GZCTF, and Zero Day Arena compare, and what each one is actually good at in a live event.
- [How to Run a CTF Competition: A Complete Organizer Guide](https://zerodayarena.com/blog/how-to-run-a-ctf): Everything you need to know about running a CTF: platform choice, challenges, infrastructure, anti-cheat, scoring, and what tends to break under real load.

## FAQ

### What is Zero Day Arena?
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.

### Who is Zero Day Arena for?
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.

### How does Zero Day Arena prevent flag sharing?
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.

### Does Zero Day Arena support Attack-Defense CTFs?
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.

### How many teams can Zero Day Arena handle?
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.

### How is Zero Day Arena different from CTFd?
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.

### How much does Zero Day Arena cost?
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.

### Who is behind Zero Day Arena?
Zero Day Arena is an independent CTF platform with its own team and roadmap. Its parent company is COPG Global.

## Policies and contact

- [Privacy Policy](https://zerodayarena.com/privacy)
- [Terms of Use](https://zerodayarena.com/terms)
- [Security & Responsible Disclosure](https://zerodayarena.com/security) · security contact: security@zerodayarena.com
- Sales and demos: hello@zerodayarena.com